Home | Ezine | Forums | Links | Contact
NitroExpress.com: Proof loads

View recent messages : 24 hours | 48 hours | 7 days | 14 days | 30 days | 60 days | More Smilies


*** Enjoy NitroExpress.com? Participate and join in. ***

Double Rifles, Single Shots & Combinations >> Double Rifles

Pages: 1 | 2 | 3 | 4 | >> (show all)
doublegunfan
.275 member


Reged: 26/04/05
Posts: 60
Loc: Brazil
Proof loads
      #41736 - 18/11/05 07:44 AM

My friends,

As some of you already know, I am converting a Beretta 411 12 ga SxS into a double rifle in .444 Marlin. The project is reaching a point in which I am almost ready to proof the gun
Now, my questions are:

1) How should I proceed with the proof test? should I load both barrels and shoot them right-left and then check the gun, or should I load one and keep the second barrel empty during the procedure?

2) What load do you recommend? I have at my disposal some quantity of IMR 3031, which is the one I plan to load with, and I was thinking of proofing the gun with the maximun load recommended for this powder/caliber.

Opinions, concerns and experiences are welcome.

Fred


Post Extras: Print Post   Remind Me!   Notify Moderator  
foxfire
.375 member


Reged: 25/11/04
Posts: 511
Loc: Long Island N.Y.,
Re: Proof loads [Re: doublegunfan]
      #41737 - 17/11/05 02:15 AM

First let me say I have no experience in this area and this is only MHO, it sounds like you don't have much experience
either. So given that I would do the following:
A. Load only one barrel and shoot and the other and shoot.
B. Start with reduced loads not full pressure loads.
C. For the first time pull the trigger with a long rope from across the room.
D. Good luck

--------------------
No good deed goes unpunished


Post Extras: Print Post   Remind Me!   Notify Moderator  
Peterb
.333 member


Reged: 07/07/04
Posts: 288
Re: Proof loads [Re: doublegunfan]
      #41747 - 17/11/05 04:19 AM

You evidently do not understand "proof loads". A proof load is NOT meant to determine whether or not that load will blow up a gun. That would determine whether that load is over the Ultimate Strength of the metal. A proof load is meant to determine whether the load exceeds the PLASTIC Strength. That is the point where the stress exceeds the point where the metal will return back to the same dimensions. To check this, the proof houses take extremely accurate measurements in specific areas before and after the firing. If there is ANY dimensional change, the plastic deformation has been exceeded and damage has been done to the gun. The gun has failed proof test. Your plan does not do this. You may do gradual damage to your gun which will possibly destro it after several shots when you mistakenly believe it is safe to shoot.

Post Extras: Print Post   Remind Me!   Notify Moderator  
400NitroExpress
.400 member


Reged: 26/11/03
Posts: 1154
Loc: Lone Star State
Re: Proof loads [Re: doublegunfan]
      #41754 - 17/11/05 05:26 AM

DGF:

The purpose of proof testing isn't to determine whether or not the gun will survive a normal load. The purpose is to be certain that the gun possesses the structural integrity to survive a load that produces an excess pressure of "X" ABOVE the normal load without damage (without exceeding the elastic limit of the structure, as Peter stated). For example, the British rules of proof require rifles to be proved with a load that produces not less than 130%, and not more than 145%, of the peak mean operating pressure of the normal load.

"Proofing the gun with the maximum load recommended for this powder/caliber" (a normal load) won't do any good because it won't tell you if you have any safety margin with a normal load or not. If you don't happen to have access to a pressure gun, it will be a trick to develop an appropriate proof load without scattering pieces. Your only option would be to get a proof house to tell you how to assemble a .444 proof load, but I can't imagine any of them being co-operative.
-----------------------------------------------------------------

--------------------
"Serious rifles have two barrels, everything else just burns gunpowder."


Post Extras: Print Post   Remind Me!   Notify Moderator  
Judson
.300 member


Reged: 21/09/05
Posts: 190
Loc: St. Albans Maine U.S.A.
Re: Proof loads [Re: doublegunfan]
      #41781 - 17/11/05 11:10 AM


For the most part all that is said here is true!!!! You should mike up your water table and for that matter all breech clearances prior to firing your proof loads. After proofing if any have changed then the gun did not work out! Steel is both elastic and plastic in action. What I mean by this is that up to a given pressure steel will compress and spring back, (Only for a given number of repititions, thus stress failure.) or distorte as when fordged. If you take a piece of steel which is properly hardened and beat it with a hammer it will up to a point spring back to shape. If the steel is to hard it may break and if not hardened the same steel will get beaten out of shape. Never hold on to a gun during proof testing as you may not live to check it out!!!!
I use the German methiod which is to take the max load for a given bullet weight/ cartridge and up the bullet weight 10 percent. Thus a 450 grain bullet max load would have a 500 grain bullet seated on to of it. Fire one proof and one standerd load from each barrel and check all tollerances. If any thing has changed then it did not pass proofing.

--------------------
It is the small calibers that are the biggest bores.


Post Extras: Print Post   Remind Me!   Notify Moderator  
mickeyModerator
.416 member


Reged: 05/01/03
Posts: 4639
Loc: Pend Oreille Valley, Idaho
Re: Proof loads [Re: Judson]
      #41790 - 17/11/05 11:56 AM

DGF

Why not invest $500 and send it to Liege or Ferlach and get it proofed properly. They will mark it as proofed, for future buyers, and you will have the piece of mind that it works.

--------------------
Lovu Zdar
Mick

A Man of Pleasure, Enterprise, Wit and Spirit Rare Books, Big Game Hunting, English Rifles, Fishing, Explosives, Chauvinism, Insensitivity, Public Drunkenness and Sloth, Champion of Lost and Unpopular Causes.


Post Extras: Print Post   Remind Me!   Notify Moderator  
doublegunfan
.275 member


Reged: 26/04/05
Posts: 60
Loc: Brazil
Re: Proof loads [Re: mickey]
      #41835 - 17/11/05 09:54 PM

Guys,

Thanks for the answers so far.

I am a Mechanical Engineer, so the explanations of the steel properties are well understood, although I am no expert in these matters.

Anyway, I think I have a good starting point based on the German rules of adding 10% to the bullet weight, as mentioned by Judson, and I will probably proceed with it. Unfortunately, it is not very simple to send a gun to be proofed overseas from here, despite the cash investment. I aggree that it would be way better to have a proof house checking the gun instead of doing it myself.

One thing I did not mention in my previous message is that I am very carefull at reloading. My loads are usually 5 to 10% less than the maximun loads listed for a given calibre, and I don't care if I am sacrificing a little bit of velocity to have a better safety margin. I always deal with these things very carefully.

I am also preparing a "quality control plan", a check list with everything I will control and measure before and after the tests. Visual inspection of the action and barrels are included, as well as measurements of the chambers, barrels and gaps. This will give me all the data to approve or reject the gun after the tests.

Fred


Post Extras: Print Post   Remind Me!   Notify Moderator  
banzaibird
.333 member


Reged: 18/09/05
Posts: 358
Loc: S.C. Pennsylvania, USA
Re: Proof loads [Re: doublegunfan]
      #41840 - 17/11/05 11:08 PM

Mickey,

That's great but who offers the service? I asked this question on a different thread and received no replies. My understanding is unless you have an import/export firearms license you can't send it yourself.

I've been reading most of these threads with interest because I've built a couple of my own DR's and currently am machining a snap action out of 4140 and would like to get it proofed when done.

The interesting thing I've learned in my reading of the proofing process is how strict it is. For example pretty much any work on the barrels at all will negate the proof. In fact if the gun is refinished multiple times and the polishing removes enough weight from the barrels they are no longer in proof.

BB


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tom_Bigbore
.224 member


Reged: 16/01/04
Posts: 44
Loc: Germany
Re: Proof loads [Re: Judson]
      #41841 - 18/11/05 12:14 AM

Judson,
what do you mean with german method? I don´t know that method and acting in the way you describe would only be used for big and unusual blackpowder calibers to not fill the barre up with 300 grains of BP. Germany follows the CIP as any of the other countries mentioned in this thread. There is no other method to proof a gun.
As already stated by someone else, the proofhouse will fire some cartridges that produce between 30 to 45% more chamber pressure as the allowable max average defined in CIP (SAAMI) for that cartridge. Measuring before and after proof firing will also be done.
br Tom


Post Extras: Print Post   Remind Me!   Notify Moderator  
iwantadouble
.300 member


Reged: 06/06/05
Posts: 104
Loc: Gallatin County, Montana
Re: Proof loads [Re: banzaibird]
      #41842 - 18/11/05 12:36 AM

In reply to:

I've been reading most of these threads with interest because I've built a couple of my own DR's and currently am machining a snap action out of 4140 and would like to get it proofed when done.




Do you have any pictures of it that you would mind sharing? Even a half cut action would be more than enjoyable to gaze upon. The building processes of anything are what hold the most appeal to me.

--------------------
500 is a nice round number, either followed by "Nitro Express" or by "cubic inch displacement".


Post Extras: Print Post   Remind Me!   Notify Moderator  
banzaibird
.333 member


Reged: 18/09/05
Posts: 358
Loc: S.C. Pennsylvania, USA
Re: Proof loads [Re: iwantadouble]
      #41843 - 18/11/05 01:03 AM

Iwantadouble,

I do have pictures. I have to scan them in to the computer. I might wait till I have the rifle further along and do a series kind of like Judson has done. At this point I'm not sure the action is going to actually work. I'm builing it from pictures and drawings as I have no snap actions (underlever) at my disposal. On top of that I decided that I was going to build it with the internals connected to trigger plate like the McKay Brown actions. I actually have that all worked out. So don't get to excited as it might not work out. When i built my first falling block rifle it took me 3 receivers to get one that functioned the way it was supposed/I wanted it to.

Tom,

I think he was referring to the west german system from 1973 and not the current CIP rules. Just for clarification though CIP and SAAMI don't necessarily have the same pressure limits on cartridges.

BB



Post Extras: Print Post   Remind Me!   Notify Moderator  
mickeyModerator
.416 member


Reged: 05/01/03
Posts: 4639
Loc: Pend Oreille Valley, Idaho
Re: Proof loads [Re: banzaibird]
      #41844 - 18/11/05 01:58 AM

Banzaibird

First you need to get in touch with the proof house, Liege, Ferlach, Birmingham wherever and find out the rules and paper work needed to have the rifle imported into that country. they will help you or put you in touch with a company over there that will.

I have just taken the rifles in question over, to Liege, on a cheap flight and avoided most of the paperwork, here and abroad. You will still need some importation documents in Holland but not in Belgium if you travel by train. If you send it, use Benelux and it will go directly to Brussels where an agent will clear the paper work.

If arranged prior to your trip they will do it on the day you want, it is a one day process and, in Liege, you can also get the barrels regulated at the same time if that is a problem. You will only be getting the final proof if the rifle is done, not the preliminary ones.

If it blows up you won't have to worry about importing back to the US If not all you will need is the normal Customs form, that you owned the rifle before you left.

I know rifles are sent from Aus to England regularly for reproofing and refinishing so some else can give you that.

--------------------
Lovu Zdar
Mick

A Man of Pleasure, Enterprise, Wit and Spirit Rare Books, Big Game Hunting, English Rifles, Fishing, Explosives, Chauvinism, Insensitivity, Public Drunkenness and Sloth, Champion of Lost and Unpopular Causes.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tom_Bigbore
.224 member


Reged: 16/01/04
Posts: 44
Loc: Germany
Re: Proof loads [Re: banzaibird]
      #41846 - 18/11/05 02:04 AM

BB,
what I meant was, if CIP "Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives C.I.P" introduce a cartridge into their datatables, every proofhouse will then take this data.
I once ordered a .400 CorBon change barrel for my 1911. As this cartridge is not in CIP the german proofhouse took the SAAMI data for proofing. Guess it is SAAMI, at least they had the information from the US.
Tom


Post Extras: Print Post   Remind Me!   Notify Moderator  
banzaibird
.333 member


Reged: 18/09/05
Posts: 358
Loc: S.C. Pennsylvania, USA
Re: Proof loads [Re: Tom_Bigbore]
      #41864 - 18/11/05 07:44 AM

Tom,

I understand what your saying now, makes sense. Just wanted to be sure that you knew that SAAMI and CIP didn't necessarily have the same pressure limits on cartridges.

Mick,

I never even thought of travelling with the gun. That makes perfect sense and would seem to make things much easier then trying to ship it, thanks.

BB


Post Extras: Print Post   Remind Me!   Notify Moderator  
unspellable
.300 member


Reged: 06/03/04
Posts: 187
Loc: Iowa
Re: Proof loads [Re: banzaibird]
      #42132 - 22/11/05 10:43 AM

If I were obliged to proof a smokeless chambered rifle for my own purposes, I would take the heaviest bullet intended for a working load. I would then take the maximum powder charge for that working load and increase it by 7%. As a back of the envelope calculation that would increase the pressure by 31%. (As a rule of thumb, pressure is proportional to the fourth power of the powder charge. Shows that you really don't want to go over max in a working load.) If the maximum charge is a slow powder case filler you may have to go to the maximum charge listed for the next faster powder and add 7% to the listed charge. Generally smokeless proof loads use a standard weight bullet with a higher or faster than normal powder charge. Use of a heavier than standard bullet is common in black powder proof loads.

If not a wildcat, the heaviest intended load would be at minimum the heaviest commercially available load now or in the past.

It should be noted, that if the pressure is too high you can have a brass failure and damage the gun even though the gun itself would be able to withstand the pressure. It's generally figured that the strongest brass may begin to flow if you go beyond 70,000 cup. Some cases will fail before that. A 444 marlin case should be fairly strong.

And tie the rifle to some tires, hide behind a big tree, and use a long long string to pull the trigger.


Post Extras: Print Post   Remind Me!   Notify Moderator  
doublegunfan
.275 member


Reged: 26/04/05
Posts: 60
Loc: Brazil
Re: Proof loads [Re: unspellable]
      #42174 - 22/11/05 10:57 PM

Unspellable,

Thanks for your comments. I was looking into every book I have (it does not seem that I have enough books) to find some data on the correlation between powder charge increase versus pressure increase.

As far as I can see from the previous messages I have learned the following (please everyone, correct me if any statement is incorrect):

1) To safely proove any gun, you must fire it remotely by means of a long string attached to the trigger and the gun must be in a sort of "fixture" that holds it in place. Shooter must be protected to avoid injuries;

2) As for the loads to be used we have two methods in discussion here:

a) Increase pressure 30% by means of increasing the powder charge of a maximum working load by 7%.

This looks like a good rule of thumb, but I think that two important considerations must be included: the proportion of charge X pressure increase may be considerably different from one powder to another, and, without any means of measuring the pressure, how can one be sure of the pressure in tests?

b) As an alternate method, increase muzzle energy 10% by means of increasing bullet weight 10% on top of a maximum working load.

Does anyone know if an increase in bullet weight would correlate to a proportional increase in pressure, i.e., if by increasing 10% of bullet weight, pressure will also be 10% higher?

As a side note, I have been thinking that, whenever someone mentions any change in a double rifle or shotgun, we tend to think of proofing or re-proofing. How many bolt action owners have rebarreled their rifles and never given any thought of re-proofing them after the change?

Fred


Post Extras: Print Post   Remind Me!   Notify Moderator  
500Nitro
.450 member


Reged: 06/01/03
Posts: 7244
Loc: Victoria, Australia
Re: Proof loads [Re: doublegunfan]
      #42178 - 22/11/05 11:30 PM

Fred

Re "How many bolt action owners have rebarreled their
rifles and never given any thought of re-proofing them
after the change ?

In the UK and other countries where their are proof laws,
you don't have an option but to reproof the gun.

However in Australia, the US etc, it is not an issue
as there are no proof laws.

500 Nitro


Post Extras: Print Post   Remind Me!   Notify Moderator  
unspellable
.300 member


Reged: 06/03/04
Posts: 187
Loc: Iowa
Re: Proof loads [Re: doublegunfan]
      #42207 - 23/11/05 06:10 AM

I don't know how much a heavier bullet would increase pressure with a smokeless load so I would stay away from that myself. My guess is that increasing the bullet weight by 10% would increase the pressure by more than 10%. Higher pressure in itself will cause the powder to burn faster. The rule of thumb that says pressure is proportional to the fourth power of the powder charge applies to any powder that is working in it's normal pressure range. Any given powder will work at its best in a certain pressure range. For example, a shot gun powder will burn smoothly in the 10000 to 15000 cup range while most slow rifle powders will not burn smoothly at such a low pressure. But it is only a rule of thumb, your milage may vary.

There are pressure measuring systems available to the individual experimenter but they have the drawback that they measure pressure relative to a given factory load rather than giving you the pressure itself. In other words you can say your handload runs 1.07 times the pressure of a given factory load but you can't say what the pressure actually is. A true pressure measurement requires a test set up that's beyond the average guy's means.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Daryl_S
.577 member


Reged: 10/08/05
Posts: 17856
Loc: Beautiful British Columbia, Ca...
Re: Proof loads [Re: unspellable]
      #42213 - 23/11/05 10:31 AM

I'm not sure a slightly heavier bullet would work as a proof. Going from 300 to 330gr. in bullet weight, usually results in only 1 or 1.5gr. powder difference in the .444 top-end loads - from memory here. Most data in various loading manuals varies more than that in itself. Inceasing pressure by 30% seems a bit drastic, but then, we-too have no proof rules here.
: Does anyone know the SAMMI standard for .444 Marlin? Is it the same as all rifle's used in that ctg. as in 44,000CUP for Marlin and WW lever guns? Is the double rifle stronger or less strong than these rifles? What is this level of pressure in PSI? or CIP for that matter?
: I think if one wants a proper proof, one needs to send it away to be done properly where proper pressure equipment is available IMHO.

--------------------
Daryl


"a rifle without hammers, is like a Spaniel without ears" Edward VII


Post Extras: Print Post   Remind Me!   Notify Moderator  
k80
.333 member


Reged: 07/05/04
Posts: 314
Loc: San Antonio ,Texas, U.S.A.
Re: Proof loads [Re: Daryl_S]
      #42218 - 23/11/05 12:03 PM

Perhaps a email to the SAMMI organization
could shed some light and reveal a U.S.
based proof house. The Shooting Sports
Foundation could also be a help.

--------------------
Ken
San Antonio

Welcome to South Texas


Post Extras: Print Post   Remind Me!   Notify Moderator  
Peterb
.333 member


Reged: 07/07/04
Posts: 288
Re: Proof loads [Re: Daryl_S]
      #42219 - 23/11/05 12:13 PM

There are proof houses in both Birmingham and London. They charge about 11-15 pounds per barrel. The greatest cost is shipping and paperwork if they do not accompany you to that point. If you have to send them, expect a cost of about $300.

First the gun will undergo visual proof. If any barrel dents, pits or looseness is discovered, the gun fails visual proof and the gun must be fixed. If the gun passes visual proof, it goes on to firing proof. IMHO, anyone who tries to do this themselves is a complete idiot.


Post Extras: Print Post   Remind Me!   Notify Moderator  
577Robert
.224 member


Reged: 10/02/05
Posts: 30
Loc: Germany, NRW
Re: Proof loads [Re: Tom_Bigbore]
      #42251 - 23/11/05 08:57 PM

Judson and Tom,
I could not resist to give you my input on this matter.
What is referred as “the German method” is actually an extract from our proof law. To the benefit of those who are able to read German ( at least Tom ) I have the original version attached. For those who are not, there is a babelfish translation where I have done some corrections attached as well. And last but not least I have attached a very simple basic translation.

But here is the original German language text which is base on the "Beschussgesetz", Anlage I der 3. VO
zum Waffengesetz, Satz 1.2.3:

„Der Mittelwert des Gasdrucks der Beschussmunition muss den zulässigen Höchstwert des Gasdruckes der Gebrauchsmunition Pmax nach den Maßtafeln, der Mittelwert des Gasdrucks der Beschussladung oder des Prüfgemisches den zulässigen Höchstwert der Gebrauchsladung oder des Gebrauchsgemisches um mindestens 30% übersteigen. Ist anstelle des Gasdruckes die Bewegungsenergie der Geschosse zugrundezulegen, so muss unter Verwendung eines gleichartigen Treibmittels der Mittelwert der Bewegungsenergie der Geschosse der Beschussmunition den zulässigen Höchstwert der Bewegungsenergie der Geschosse der Gebrauchsmunition Emax nach den Maßtafeln, der Mittelwert der Bewegungsenergie der Beschussladung oder des Prüfgemisches den zulässigen Höchstwert der Gebrauchsladung oder des Gebrauchsgemisches um mindestens 10% übersteigen. Kann mit der zur Verfügung stehenden Munition, der Ladung oder dem Gemisch die erforderliche Energie nicht erreicht werden, so ist unter Beibehaltung des Treibmittels ein Geschoss zu verwenden, dessen Masse um mindestens 10% höher ist als die der Gebrauchsgeschosse.“

Here is a translation using the babelfish webpage:
"The average value of the gas pressure of the proof ammunition must exceed the permissible maximum value of the gas pressure of the regular ammunition (Pmax) based on the listings in measure boards, the average value of the gas pressure of the proof charge or the test mixture the permissible maximum value of the regular charge or the regular mixture, by at least 30%.
If the kinetic energy of the bullets is to be taken as a basis in place of the gas pressure, then the average value of the kinetic energy of the bullets of the proof ammunition must exceed the permissible maximum value of the kinetic energy of the bullets of the regular ammunition Emax ( max energy ) based on the listings in measure boards, the average value of the kinetic energy of the proof charge or the test mixture the permissible maximum value of the regular charge or the regular mixture around at least by 10% using a very similar ( the same ) propellant.
If the necessary energy cannot be achieved with the ammunition, the charge or the mixture, that is available, then a projectile is to be used, which weight is at least 10% higher than those of the regular projectiles while maintaining the same propellant."

In short
a) the pressure of the proof load must be at least 30% higher that the service pressure.
b) if the energy is used as an indicator, the proof load must achieve a 10% higher energy that service ammunition while using a similar powder.
c) if the above is not possible than use a bullet which weight is at least 10% higher than service ammunition with the use of the same powder.
For example to c) Service ammunition .308 Winchester with a 150 grains, bullet pull the bullet and substitute it with a 165 grain bullet and use the same and same amount of powder.
The use of the energy ( as stated in b) as an indicated is not uncommon. I have used that at least two times with different German proof houses in the past. Recalculation of the energy back to the velocity gives you a very good indicator when you have reached the requested minimum increase of 10%.
I hope this helps a little bit on understanding the "German method"
best regards
Robert


Post Extras: Print Post   Remind Me!   Notify Moderator  
doublegunfan
.275 member


Reged: 26/04/05
Posts: 60
Loc: Brazil
Re: Proof loads [Re: 577Robert]
      #42259 - 24/11/05 12:48 AM

Robert,

Thank you very much for the information you have posted. It certainly helped a lot to clarify the matter.

In fact, I have never personally given much attention to proofing. The only occasion in which I had any experience in this area in the past was one visit a few years ago to the Imbel plant (the same factory that produces our Army FAL's and Springfield Armoury's 1911 .45ACP pistols). During that visit, I could see the proofing of a few FALs and pistols. This is routinely done at the factories, and they use special cartridges especifically loaded for that purpose by Magtech/CBC. Unfortunatelly, this is not a service they provide to the general public, and Magtech/CBC does not produce ammo (regular or proof) for the .444.

Even so, I am more confident now that I can come up with a good proof load that will give me the desired sense of the safety of my project gun. I tend to aggree with some of you in that proofing is something best left to especiallized proof houses. But I would feel even more idiot if I decided to build a gun and shoot it without any form of testing!!!

Fred


Post Extras: Print Post   Remind Me!   Notify Moderator  
500Nitro
.450 member


Reged: 06/01/03
Posts: 7244
Loc: Victoria, Australia
Re: Proof loads [Re: Peterb]
      #42260 - 24/11/05 01:33 AM


Peterb

One thing you forgot after:-

"If any barrel dents, pits or looseness is discovered, the gun fails
visual proof and the gun must be fixed. If the gun passes visual proof,
it goes on to firing proof."

If it fails proof, they can and will cut the barrels up !!!

I do agree with you though that without any form of pressure
barrels / testing equiment "anyone who tries to do this themselves
is a complete idiot."

Some times a little information is dangerous !

500 Nitro


Post Extras: Print Post   Remind Me!   Notify Moderator  
Peterb
.333 member


Reged: 07/07/04
Posts: 288
Re: Proof loads [Re: 500Nitro]
      #42275 - 24/11/05 08:58 AM

The problem I see with the self proofing is that I don't believe the home proofers have any idea of how and where to measure before and after firing. Without this information (and ability), nothing is proved or proofed. One might simply be gradually destroying the gun resulting in a catastropic failure later when the gun is being fired by a human. I say this not to belittle anyone but to try to keep them safe.

Post Extras: Print Post   Remind Me!   Notify Moderator  
doublegunfan
.275 member


Reged: 26/04/05
Posts: 60
Loc: Brazil
Re: Proof loads [Re: Peterb]
      #42312 - 24/11/05 10:09 PM

"The problem I see with the self proofing is that I don't believe the home proofers have any idea of how and where to measure before and after firing. Without this information (and ability), nothing is proved or proofed."

Well, what can I say? If you don't know it, don't take for granted that nobody knows it too.

Fred


Post Extras: Print Post   Remind Me!   Notify Moderator  
Peterb
.333 member


Reged: 07/07/04
Posts: 288
Re: Proof loads [Re: doublegunfan]
      #42319 - 25/11/05 03:48 AM

...and if you don't know it and cannot accurately measure it, don't do it. If you do know it, why ask about it?

Post Extras: Print Post   Remind Me!   Notify Moderator  
Judson
.300 member


Reged: 21/09/05
Posts: 190
Loc: St. Albans Maine U.S.A.
Re: Proof loads [Re: Peterb]
      #42882 - 03/12/05 10:57 AM


One learns by asking questions and using common sence.
The measurements you need depend on the type of action you are working with but all these can be obtained from the manufactuer or by measuring all areas of a tight action of the same make. Basically if any measurement changes from the pre proof measurement to the post proof measurement then the gun failed!!! Properly hardened steel is up to a point elastic and will spring back to it's origional dementions. if it does not either you are higher in pressure then the action will take or you have a soft action and it will beat it self out of shape over time and become unsafe. If you measurements change during proofing junk it and start over, no gun is worth a life!

--------------------
It is the small calibers that are the biggest bores.


Post Extras: Print Post   Remind Me!   Notify Moderator  
hoppdoc
.400 member


Reged: 02/03/06
Posts: 1791
Loc: Southeastern USA
Re: Proof loads [Re: Daryl_S]
      #53223 - 24/03/06 10:33 AM

Fascinating Thread!!

I think I understand proofing.I assume the conditions to proof are standardized and proof loads should generate at least 30% more pressure than standard.7% more powder should generate at least 30% more pressure

From what I have read a boxlock action is structurally weaker than a bolt action.
How much pressure can each one stand?

From this discussion I assume I should use the table powder charge as the absolute max for doubles even if the velocity is sub par. I assume the powder charge is the limiting factor since pressure is related to the 4th power of the charge used.

This is a big difference from how I load rifle shells. I chrono and attain the velocity desired(compensated for barrel length) and then lower the charge progressively till the most accurate combo is found. Max may be several grains over the powder tables max.
Never had any problems cause I hunt bolt actions in cooler mountainous hunting seasons but I quess that the strength of the bolt action may be more forgiving than a boxlock.

Looks like loading Doubles is touchier with the powder charge and filler et al.Add to that you hunt in hotter climates that cause higher firing pressures


--------------------
An armed man is a citizen of his country, an unarmed man just a subject.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Daryl_S
.577 member


Reged: 10/08/05
Posts: 17856
Loc: Beautiful British Columbia, Ca...
Re: Proof loads [Re: hoppdoc]
      #53319 - 26/03/06 04:05 AM

Just a note of warning. Most modern books have very realistic maximum pressure listed since now changing over the to PSI method of measurement. They sometimes aren't at the top of what 'some' brass can stand, but are maximum loads established by the international association called SAAMI.
: It is not a good idea to exceed these posted maximum loads. I've had many rifles that maxed out before I even got to the book maximums, so!
: Please be careful.
: Only European countries (including the UK) have proof testing laws as actually proof test.

--------------------
Daryl


"a rifle without hammers, is like a Spaniel without ears" Edward VII


Post Extras: Print Post   Remind Me!   Notify Moderator  
hoppdoc
.400 member


Reged: 02/03/06
Posts: 1791
Loc: Southeastern USA
Re: Proof loads [Re: Daryl_S]
      #53340 - 26/03/06 03:02 PM

For absolute safety you are correct-

With factory bolt rifles I have only ended up 2-3 grains over max without other signs of excessive pressure with sticky bolts, primers problems, or brass expansion.Hunting for max accuracy with backing the bullet off the lands and dropping the charge usually finds that powder charge down signifigantly.If the measured velocity is TOO HIGH for the reload you will have too much pressure no matter what you notice with the brass!! I have an accurate 270 with a longer throat that likes a hot load and tolerates it well reaching slightly below standard 270 max velocities.

I will say that if the bolt rifle has a tight or MATCH chamber, everything goes out the window and usually you never see the max charge allowed. I have a match 308 bolt gun that taught me that lesson. If factory ammo is tight going thru the gun--BEWARE!! Starting 15% down and working up is good advise on those guns.

For Big Doubles I will assume the powder charge should be 10% down from max and you work your way up to the recommended max accuracy/regulation or until pressure signs stop you. I bet there isn't a Buff alive that would notice the difference in backing off 50-100fps if your load is accurate and you put the bullet in the right place.

--------------------
An armed man is a citizen of his country, an unarmed man just a subject.

Edited by hoppdoc (26/03/06 03:13 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Daryl_S
.577 member


Reged: 10/08/05
Posts: 17856
Loc: Beautiful British Columbia, Ca...
Re: Proof loads [Re: hoppdoc]
      #53363 - 27/03/06 03:11 AM

Right-on. I wasn't sure you had everything in perspective from the previous posting. I see you're in charge.
: My 7X57 and 6.5X55, of course, go past most max listed loads (except for Barnes data on XLC bullets), and the wildcats I shoot are probably all being loaded to well over 60,000PSI, in the 65,000PSI range as is normal for many modern rounds with both failry straight and sloping shoulders. The chronograph is an excellent instrument for weeding out the drop in efficency as max comes along. My Ruger 31 in .218Bee, .22 CZ Hornet, 6.5x55, 7X57 and .375/06IMP all give best accuracy when pushing the max pressure envelope, while others are happiest back a couple grains.
: Tight chambers with SAAMI necks usualy take top-end loads in stride.
: I like Barnes listed proceedure for finding max laods and an accuraate powder in one fell swoop. If you dont' have their handloading book, it is a good one for the library. They start with the low laod, and load one each with each increase from there by 1 gr. and shoot them as a group watching for pressure signs. The most accurate powder is the one used. This is a good method, as temperature fluctuations give varried velocities and vibrations and usually a given powder will show an overall better accuracy result. The powder that gives the best overall accuracy from start to max is the one used in load development.

--------------------
Daryl


"a rifle without hammers, is like a Spaniel without ears" Edward VII


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bramble
.375 member


Reged: 29/07/06
Posts: 950
Loc: England
Re: Proof loads [Re: Daryl_S]
      #71290 - 12/02/07 06:48 AM

I should like to add to this thread my experiences from the London proof house last week.

There are apparently three methods.

If the cartridge is current and common, they may have an assembled proof load in hand.

For my .450#2 they did not and I was asked to bring primed cases and heads into which they were going to assemble a proof load in blackpowder. However they only do this with lead bullets.

When they discovered that I had Woodleigh solids they decided to use my service load which was near maximum and they took the cases and oiled them liberally before firing the rifle.

The rifle was fired with the foreend detached.

Both barrels were loaded alough they were fired one by one.

The examination before and after was visual and physical. Checking that the rifle was on face, examining the bore and chamber.

Immediatly after firing the technicion removed the rifle from the chamber and before opening it held the breach up to the light to check for any gap opening between the barrels and the action face. He then opened the rifle and removed and examined the cartridges remarking on the ammount of primer extrusion indicating the pressure levels. Both primers were volcanic in extrusion and one had a burr forced up that I could remove with a thumb nail. He examined the chambers and the exterior of the barrels. No measuring equiptment was used.

He did remark to me that a similar process had knocked the .600 from a major manufacturer off the face just a couple of weeks earlier.

My rifle was stamped up as proofed to CIP limit of 3500 BAR.

My 6mm BR Norma Ruger #1 was proofed to the same method at the same time using my Lapua factory rounds again because of the relative rarity of the round.

Hope this information helps somebody in the future.

Regards


Post Extras: Print Post   Remind Me!   Notify Moderator  
308
.275 member


Reged: 26/01/07
Posts: 61
Loc: Wangaratta/Victoria/Australia
Re: Proof loads [Re: Bramble]
      #71318 - 12/02/07 02:45 PM

Bramble,
I am looking at getting a rifle proofed in London, I am in Australia, do you have their email or website? or know any London gundealers who can help with this? Thanks

308

Edited by 308 (12/02/07 02:47 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Raff
.300 member


Reged: 12/01/04
Posts: 182
Loc: Texas
Re: Proof loads [Re: 308]
      #71337 - 13/02/07 02:38 AM

www.gunproof.com

Birmingham Proof House, nice folks.

Raff

--------------------
.


Post Extras: Print Post   Remind Me!   Notify Moderator  
larcher
.416 member


Reged: 11/01/05
Posts: 2651
Loc: Saverne, Alsace, France
Re: Proof loads [Re: Raff]
      #72815 - 01/03/07 05:37 AM

You can have Your gun tested in France also

banc officiel de St Etienne

--------------------
"I don't want to create an encyclopedic atmosphere here when we might be having a beer instead" P H Capstick in "Safari the last adventure."


Post Extras: Print Post   Remind Me!   Notify Moderator  
pistolchamp
.224 member


Reged: 27/02/07
Posts: 19
Loc: Texas, USA
Re: Proof loads [Re: larcher]
      #74905 - 29/03/07 05:38 AM

After having worked with a major ammo manufacturer for several years and witnessed their proof loading and loads, I can assure you that NO individual has the time, experience or equipment to do this properly.

Industrias Technos S. A. de C. V. in Mexico made up special pressure test loads for each caliber they manufactured to a specific pressure as dictated by CIF and/or SAAMI, different loads for each caliber depending on which outfit was in charge in the country they expected to sell the ammo.

They have state-of-the-art pressure barrels and testing equipment that you and I could not possibly afford and if we could we wouldn't know how to use it.

After witnessing hundreds of proof loads fired in calibers from 22 short to 50 BMG, I can assure you it is not a project for the faint of heart. The occasional blowup of a firearm in their armored testing vault was simply par for the course... and they did not make guns, only ammo.

Call me chicken, but, I am not firing any rifle, pistol or shotgun that has not been proofed by a professional company. Way to scary for me.

I watched an idiot load a Ruger #1 in 7 m/m Rem Mag with a 175 grain bullet over a full case of Bullseye and pull the trigger with a long string. The rifle jumped about ten feet high (I'd give anything for a chrono, but, didn't have one), broke the stock at the wrist and had to be pounded open with a deadblow hammer. The action was seriously sprung and destroyed for further use as a rifle... amazing to me was that it did not explode... I guess they are pretty strong.

Making double rifles from shotguns has been done a lot, but, remember your average shotshell only developes about 10,000 psi or a lot less and your average rifle caliber such as the aforementioned 44 Marlin operates at up to 44,000 psi, and the 375 H&H can get to 62,000 psi... a lot of difference for that shotgun action to take.

My advice, save your money 'til you can buy a real double rifle (it doesn't have to be a Holland) and you'll be much happier and safer.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bramble
.375 member


Reged: 29/07/06
Posts: 950
Loc: England
Re: Proof loads [Re: pistolchamp]
      #74934 - 29/03/07 09:49 AM

Pistol champ.

With respect. The limiting factor for most doubles is breach thrust not absolute pressure itself although one is proportional to the other and case diamiter. There is no reason to expect a correctly built double either at home of by a major manufacturer to be unsafe with the rounds mentioned. If we take the case of the 44 marlin ( I have one) the barrel shank diamiter is less than the one on my double and thats not a guess I've rebarreled one so hoop stress is not an issue. The breach thrust @ 44,000psi of that 44 Mag is 7213 Lbs. The breach thrust of my donder 12 gauge in its origional chambering which is proofed at 1370 bar is 10,453 lbs.

I agree I would not fire a built double by anybody until it had passed a proof testand indeed the very first round fired in mine was done at the London proof house under controlled conditions.

That home built double is now proofed to 3500 bar and a breach thrust of 13109 lbs, double that of a 44 mag.

As to the 375 H&H, that high pressure is the reason that there is a 375 H&H Flanged for double guns that runs at a lower pressure.

Again with respect mine is a "real" double rifle. Many of what are regarded as classics now were made in London in workshops not much bigger than mine on trade shotgun actions purchased in the white. My double shoots 2" off hand groups at 50 mts with full out hunting loads. That is as real as it gets.
No I wouldent be happier with a purchased, cheep gun (I can afford one). I will be delighted with my first hunt with the gun I built. I was like a scrapyard dog with two cocks when it regulated to 1" at 25 mts, it is a part of me in the way that nobody elses product could ever be. It is unique, a phone call from my firearms department confirmed that today as they couldent enter it on the London polices computer, as they don't have a paramiter for it, as nobody else in London has one in that old caliber. I cant buy that.

Regards


Post Extras: Print Post   Remind Me!   Notify Moderator  
9.3x57
.416 member


Reged: 22/04/07
Posts: 4713
Loc: Idaho
Re: Proof loads [Re: Raff]
      #80191 - 08/06/07 11:41 PM

Very interesting thread.

Couple things:

First, regarding the statements that no dimensional change is allowed as a result of the proofing process, I guess it depends on the proofing process. In its discussion of the proofing of service Lee-Enfield rifles, the British "Textbook of Small Arms 1929" states that in fact some measurable dimensional change does occur as a result of proof and it is intended to do so. That is, the proofing process was partly used to seat the locking lugs, etc. Additional machining to final dimensions was conducted after proofing also, another curious event I always considered a "no-no".

Second, I watched rifle proofing at the Musgrave Mauser plant in Bloemfontein, RSA in 1985. I may not have seen the entire process, but what I saw was this: A rifle was hand-held in a steel box, a round of ammo chambered, the lid to the box closed and the round fired by hand. I believe IIRC two rounds were fired per rifle. This occured very quickly and thus a number of rifles were tested in a short time. The rifle was then handed off to another guy and it was visually inspected, but I at no time saw any measurements taken of the rifle. The whole process was very fast and, to a layman, "unscientific". It is certainly possible that rifles were measured for dimensional changes when I wasn't present, but I didn't see this occur and it was my understanding at the time that the process I saw was IT.

I have a gut feeling based on my observations and the comments of Bramble above that "proofing" may not be the exact science some would believe, and in fact, functional testing of a sort may be exactly what it demonstrates, particularly in the absence of pressure-tested ammunition. I read somewhere else a description of proofing quite similar to Bramble's also, with similar comments on the fact that the actual pressure of the ammo used to proof the gun was unknown.

We must remember, that whether our rifles are proofed or not, we may nullify the relevance the proofing may have had every single time we work up a new handload. Truth is, most of us have really no clear idea what pressures our handloads generate, only that they work and don't result in a face full of flying metal.

Indeed, in some cases {pun intended} the proof process may tell us more about the brass case than the gun. Looking at it from the other side, I read once a comment by an astute observer that looking for pressure signs on cases may be immaterial in guns that are "weaker" than the case, meaning of course that by the time we see significant pressure signs on the case, damage may have already been done to the gun. A case may fail at 70,000 psi, but if the strength of the action is 65,000 psi, well, you get the picture. And putting it another way, testing the ability of a really strong action to handle a ruptured case by purposefully weakening the case before firing it would be a nice aspect of proof but it is, of course, not done. Truth is, we trust the gunmaker in many ways, and those who think their gun is "safe" because it was "proved" may be deluding themselves a little bit more than just a little bit.

I'll go so far as to say this: "Proofing" demonstrates only that on a particular day Gun A was fired with Load A and it didn't come apart. We cannot assert how many rounds of Load A Gun A will fire before letting go and we cannot assert that the mere firing of one or two rounds of Load A means the gun will safely stand some number of rounds of Load B. That is why the specific load is marked on the gun as proof.

In effect, those of us that are handloaders "proof" our guns every time we work a load up and we shouldn't forget that. The safety margin of design and material is an unknown quantity.

As for American guns being proofed, they are. "After the fact" they are proofed by judges in courts of law. I submit, as much as I am disgusted by our legal process in-general, that this method is every bit as effective as that produced in other nations' proof houses.

And a final case in point: Every low number Springfield rifle that blew up in its firer's face whilst firing regulation service ammunition had passed "proof" before issue. And so had all the recalled SAKO 75's...

--------------------
What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?

Edited by 9ThreeXFifty7 (09/06/07 02:15 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Marrakai
.416 member


Reged: 09/01/03
Posts: 2687
Loc: Darwin, Top End of Australia
Re: Proof loads [Re: 9.3x57]
      #80232 - 09/06/07 08:52 AM

Dunno quite what you mean by this:
"A case may fail at 70,000 psi"
Without the chamber-walls, I presume a case would fail at 1000 psi!
Case failure, in the absence of any rifle failure, would be markedly affected by breech design, extractor type & fit esp. width of extractor cut, etc.

In Musgrave's case, they may have 'proved' the action during the design phase, using very stiff measured proof loads and a rigorous scientific measurement process, and simply prove each individual rifle for function as a formality, or perhaps for legal reasons.

--------------------
Marrakai
When the bull drops, the bullshit stops!
--------------------------------
www.marrakai-adventure.com.au


Post Extras: Print Post   Remind Me!   Notify Moderator  
9.3x57
.416 member


Reged: 22/04/07
Posts: 4713
Loc: Idaho
Re: Proof loads [Re: Marrakai]
      #80237 - 09/06/07 09:37 AM

Quote:

Dunno quite what you mean by this:
"A case may fail at 70,000 psi"
Without the chamber-walls, I presume a case would fail at 1000 psi!
Case failure, in the absence of any rifle failure, would be markedly affected by breech design, extractor type & fit esp. width of extractor cut, etc.

You are right. Not worded well on my part. Point is that an action design may allow a case failure long before the strength of the action is compromised, and on the other hand an action may have sufficient case support to hold the case together until the whole thing lets go.

In Musgrave's case, they may have 'proved' the action during the design phase, using very stiff measured proof loads and a rigorous scientific measurement process, and simply prove each individual rifle for function as a formality, or perhaps for legal reasons.




I was told that the process I was observing was the proofing process. As I remember, the fellow firing the gun was not an employee of Musgrave, but rather a regulatory {Proof House?} officer. This was in 1988 so if anybody knows the law in RSA at the time they might shed some light on it.

--------------------
What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?


Post Extras: Print Post   Remind Me!   Notify Moderator  
Vinnie
.224 member


Reged: 05/06/07
Posts: 8
Loc: New York. Dutchess
Re: Proof loads [Re: Peterb]
      #80884 - 18/06/07 09:20 PM

I am going to ( my first) convert a springfield SXS to a DR and would like to do a 45-70 or larger . Any suggestion or comments would be appreciated.
Vinnie


Post Extras: Print Post   Remind Me!   Notify Moderator  
9.3x57
.416 member


Reged: 22/04/07
Posts: 4713
Loc: Idaho
Re: Proof loads [Re: Vinnie]
      #80889 - 18/06/07 10:31 PM

Vinnie:

As I read this post over again it seems to me there are two "camps" of thought surrounding the proofing of a gun.

It seems some might assert the only way to proof a gun is to have it done by a proof house. The other seems to assert that some practical form of proofing can be done by an individual.

My opinion is that there is some value in having the proof done by a proof house in that a little stamp can always be pointed to if you should ever want to sell the gun or if someone should ever be injured or hurt in the firing of it. In fact, depending on where the gun is being used, there may indeed be legal requirements to have the gun proofed.

Having said that, as a practical matter I believe some have misplaced faith in the process. A proof house stamp does NOT mean a gun is "safe". It only means it was capable of handling a certain load on a certain day. Read the thread and you'll get the gist of that.

So I believe you CAN prove your own gun. As mentioned above, we all do it all the time when working up new loads and in the USA when guns are rebarrelled, custom-made, etc.

Some may have differing opinions as to the validity of proof house proof, but I am going to guess that most or all of us will agree that if you do not have the gun proofed at a proof house you are on your own and must concoct a load and a procedure. I doubt anyone is going to say "Do this, this and this and you will be safe". At least I won't!

As a practical note regarding the .45-70, it is a perfect example of a cartridge that is "proofed" by individuals all the time. Factory ammo from Remington and Winchester is typically of the "Trapdoor Acceptable" variety, yet other custom ammo is available and many common and standard handloads are used which I suspect considerably exceed "Remchester" pressures all the time. Right there you are going to have to decide whether your gun is going to handle 15k cup stuff or double that on a regular basis. Am I going to have a clue whether your home made double will handle loads I commonly shoot in my Marlin? No way...

--------------------
What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?


Post Extras: Print Post   Remind Me!   Notify Moderator  
dnovo
.333 member


Reged: 21/02/05
Posts: 490
Loc: Chicago & SE Wisconsin
Re: Proof loads [Re: 9.3x57]
      #80899 - 18/06/07 11:22 PM

I witnessed an unplanned and potentially dangerous 'home proofing' at our local rifle range last year. A handloader was trying out some hot 45-70 loads in a Pedersoli Kodiak double. Apparently not paying attention to what he assumed was a warning about loads suitable for modern lever actions such as the Marlin, and also being a bit sloppy about how much powder he dumped in trying to see how high he could get the numbers on the chrono, he handsomely exceeded 'proof' on his $3,000 double. Fortunately, none of the flying metal hit anything, but unfortunately, he walked away unscratched. He is no longer permitted at the range.

One of the range officers is a DR collector and rebuilds many older BPE and works up loads for these and his more modern DRs. We have an agreement at the range that those of us who shoot doubles regularly will run our loads past him befor we shot. Dave

--------------------
Time Wounds All Heels


Post Extras: Print Post   Remind Me!   Notify Moderator  
Vinnie
.224 member


Reged: 05/06/07
Posts: 8
Loc: New York. Dutchess
Re: Proof loads [Re: 9.3x57]
      #80900 - 18/06/07 11:33 PM

Peterb:
Thanks for the reply I will not be hunting just going to the range and enjoy shooting . I will not be loading the cartarge more than the factory loads. I would like to over proof the gun once as E.Brown describes in his book w/ a 30% higher load for one shot in each barrel. From what I read a 7% over charge will give a 30% proof psi load. Has any one done this w/ a springfield and what has been their experience.
Vinnie


Post Extras: Print Post   Remind Me!   Notify Moderator  
enfieldspares
.224 member


Reged: 12/07/07
Posts: 35
Loc: Great Britain
Re: Proof loads [Re: Peterb]
      #83020 - 25/07/07 05:36 AM

It certainly was, and is, still possible to walk into the Proof Hopuse in Birmigham, England literally "off the street" and ask that a weapon be proved "on demand". You will pay a 50% premium on the normal price and have a wait of about twenty minutes.

With an uncommon calibre usch as you have, a contact some weeks before would be useful. It would be quite possible to send the gun via a courier service to the Proof House, anyway.

The British gun laws, BTW, do NOT apply to arms that are being submitted to proof so,I don't know if you would require any export or import formalities. I would wrtie both to the Proof House AND to the British Embassy to ask questions about that aspect.

Good luck with your rifle.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rich
.224 member


Reged: 07/12/06
Posts: 25
Loc: Fayette county Pa.
Re: Proof loads [Re: Vinnie]
      #83533 - 04/08/07 11:56 AM

Vinnie, I can tell you first hand you dont want to build a 4570 on a springfield action. I put them in the same class as cast iron actions. the locking system is not strong enough. I have been building double rifles for 40 years and semi retired. If you want a cheap action to build a 4570 on try a Baikal. They are very strong and work well if you keep the pressure to 35,000 lb. I have built 17 to date on them. I still have the first one and have put 40 shots through it that are over what is recomended for a Marlin. This certain gun has over 600 rounds fired through it. 54 grs. imr. 3031 with 350 gr. Hornady and ww primer. This is the standard load i regulate them for. I use the 20 gauge for 4570 it makes a nice 8 lb Rifle. Rich [image][/image]

Post Extras: Print Post   Remind Me!   Notify Moderator  
400NitroExpress
.400 member


Reged: 26/11/03
Posts: 1154
Loc: Lone Star State
Re: Proof loads [Re: hoppdoc]
      #84702 - 27/08/07 06:38 AM

In handloading for big doubles, this:

Quote:

For Big Doubles I will assume the powder charge should be 10% down from max and you work your way up to the recommended max accuracy/regulation or UNTIL PRESSURE SIGNS STOP YOU.




...is a fairly reliable method of accomplishing this:

Quote:

...he handsomely exceeded 'proof' on his $3,000 double. Fortunately, none of the flying metal hit anything




For large bore double rifle rounds, by the time you see conventional pressure signs you're in the Twilight Zone. Most folks accustomed to handloading for bolt rifles simply can't grasp this for some reason.

Most doubles are built in CIP member countries, and are therefore proved to CIP standards. In member countries, CIP standards are not industry standards like SAAMI's, they're law. CIP requires proof cartridges for rifles to produce a mean pressure equal to 125% of permissable Maximum Average Pressure. The large flanged nitros are low pressure rounds.

For example, the .470 Nitro Express has a CIP standardized MAP of 39,160 PSI. That means that, by law, the cartridges used to PROVE a new .470 Merkel, Heym, Krieghoff, Purdey, etc., produce 48,950 PSI. When do pressure signs start on modern drawn brass cartridge cases, and modern stainless boxer primer cups? Engineers at manufacturers like Hornady usually say around 62,000 PSI. By the time conventional pressure signs begin to appear on handloads, you're WAY past PROOF. Pressure signs simply can't be safely used as a guide when handloading for doubles. They can only tell you when you've already screwed the pooch, badly.

Personally, I wouldn't have anything proved in London until they can get the current idiot Proofmaster down the road. Better to use Birmingham.

--------------------
"Serious rifles have two barrels, everything else just burns gunpowder."

Edited by 400NitroExpress (27/08/07 03:00 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
9.3x57
.416 member


Reged: 22/04/07
Posts: 4713
Loc: Idaho
Re: Proof loads [Re: 400NitroExpress]
      #84704 - 27/08/07 06:47 AM

Quote:

For example, the .470 Nitro Express has a CIP standardized MAP of 39,160 PSI. That means that, by law, the cartridges used to prove a new .470 Merkel, Heym, Krieghoff, Purdey, etc., produce 48,950 PSI. When do pressure signs start on modern drawn brass cartridge cases, and modern stainless boxer primer cups? Engineers at manufacturers like Hornady usually say around 62,000 PSI. By the time conventional pressure signs begin to appear on handloads, you're WAY past PROOF. Pressure signs simply can't be safely used as a guide when handloading for doubles.




Excellent point and well said.

This very same point has been made in the past about the working up of loads for various lever guns. For example, the guy satisfied with loads backed off just a bit to eliminate flat and cratered primers in an old Marlin 36 or Winchester 94 may even so be straining the action. I think your point needs to be heeded by anybody loading for any break action, lever, pump {like the Rem 14, etc} or other oldie like a Snyder or Trapdoor Springfield.

--------------------
What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?


Post Extras: Print Post   Remind Me!   Notify Moderator  
bonanza
.400 member


Reged: 17/05/04
Posts: 2335
Loc: South Carolina
Re: Proof loads [Re: Marrakai]
      #84712 - 27/08/07 08:37 AM

My brother has considerable experience in converting new shotguns into rifles. It's all very logical if one sticks with what has always worked.

1: Start with 4130 PAC-NOR steel rifle barrels.
2: For 12g 50-90 or 50-140, for 16g 45-120.
3: You want to duplicate Nitro for black loads only.
4: 45-70 is ok with trapdoor loads only.

You want to keep pressure at 10 tons or less. The gun will hold up.

Albeit, you won't be able to flatten a Buff with one of these you sure can drop anything in NA.


Post Extras: Print Post   Remind Me!   Notify Moderator  
beleg2
.375 member


Reged: 15/08/07
Posts: 591
Loc: Bahía Blanca - Argentina
Re: Proof loads [Re: bonanza]
      #85037 - 02/09/07 01:59 PM

Hi,
Any advice on Black powder proof charges?
I would like to reproof (home made proof) my Snider double rifle as it have been abused by previous owners. I have shot more then 60 times without any problem but just want to be shure.

Standard Snider charge was 70gn of FFg over a 480gn lead bullet.
Im thinking about something like 90-100gn of FFFg (the only powder I can get) onver 510gn bullet.

Any advise will helps.
Thanks
Martin


Post Extras: Print Post   Remind Me!   Notify Moderator  
Grenadier
.375 member


Reged: 20/02/08
Posts: 570
Loc: North of the Columbia, USA
Re: Proof loads [Re: doublegunfan]
      #97739 - 27/02/08 12:06 PM

Proof loads? Why bother? You have already exceeded the design pressures for the action you have chosen. SAAMI Maximum pressures for the 12 gauge are 11,500psi and for the .444 Marlin they are 42,000psi. You may have put some stronger barrels in the gun but the action is still a shotgun action. Here is something I posted on another site regarding what you are doing:

"I had a conversation with Paul Jaeger several years ago about making a .375 O/U on a Ruger shotgun. He had done some conversions like that before and chose the Ruger because of the strength of the action. He said he was no longer converting them because of "problems". I asked what the problems were and he went into a discussion centered around the weaknesses of a shotgun action and problems of overworking it. He mentioned double firing. He mentioned setback. He mentioned safety. A well known USA double rifle manufacturer also gained some early notoriety by converting Ruger shotguns to double rifles. You can sometimes find those early guns for sale online, most often in in .444 Marlin or .375H&H. These days, they refuse to do a shotgun conversion - for good reason.

But bold individuals continue to make cheap conversions using ... shotguns as the basis. I wish them good luck and hope they continue to keep all their fingers. After all, anything works until it breaks."

I would think an engineer would have a good grasp of what's going on. I say, if you really must, take it out and shoot it till it either scares you or blows up.

Good luck.

Grenadier

--------------------
~


Post Extras: Print Post   Remind Me!   Notify Moderator  
Marrakai
.416 member


Reged: 09/01/03
Posts: 2687
Loc: Darwin, Top End of Australia
Re: Proof loads [Re: Grenadier]
      #97855 - 28/02/08 02:07 PM

Grenadier:
You are right to advise caution with shotgun conversions, but the sheer number of these things in common use today with no safety issues whatsoever, my own .577 Light Nitro included, might prove your overall assumption incorrect.

Regarding your comparison of 11,500 psi vs 42,000 psi: the basal area of the Marlin case is only a fraction of the basal area of the 12-bore shotshell, so the back-thrust on the action is probably in the same ball-park. With the much thicker chamber-walls of the .444 on a 12-bore action, no worries about barrel strength.

Having said that, the BP load suggested in beleg2's post is a little high and would not be something any of us would recommend for a vintage rifle.

--------------------
Marrakai
When the bull drops, the bullshit stops!
--------------------------------
www.marrakai-adventure.com.au


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarg
.400 member


Reged: 20/01/07
Posts: 1141
Loc: New Zealand Australia South A...
Re: Proof loads [Re: Marrakai]
      #97874 - 28/02/08 07:51 PM

I say guys ! you may have the wrong end of the stick here , he wants to reproof factory rifle with home load !
His rifle , I believe is FACTORY double in Snider cartridge !?

--------------------
No poor bastard ever won a war by dying for his country. He won it by making other bastards die for their country.

- General George S. Patton


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bramble
.375 member


Reged: 29/07/06
Posts: 950
Loc: England
Re: Proof loads [Re: Grenadier]
      #97903 - 29/02/08 04:25 AM

Grenadier.

You cannot proove an action, only a barrelled action.

The proof pressure of the 12G doner action is irrelivent, it is limited by the chamber wall thickness not the lug sheer strength.
As Marrakai pointed out the thrust is the important figure.

If somebody insists in converting a Ruger O/U which is not a great shotgun base to begin with, into a double using .375H+H which was never designed to be fired in a double rifle then any problems could be likley anticipated.
But .444 on a good S/S action will not move in a lifetime. The thrust bearing area is so much greater than a lever action rifle for which the cartridge was designed.

Regards


(edited because I was being a grumpy old prick )

Edited by Bramble (29/02/08 08:08 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Grenadier
.375 member


Reged: 20/02/08
Posts: 570
Loc: North of the Columbia, USA
Re: Proof loads [Re: Marrakai]
      #97916 - 29/02/08 05:08 AM

Marrakai,

You are correct regarding the back thrust. However, there is more to consider. For example, steel has some elastic properties that are much like Silly Putty. You can give Silly Putty a slow pull and it will stretch a great deal. But if you give it a rapid pull it won't stretch, it will break. The pressure curves created by firing shotgun shells and rifle cartridges are very different. The rifle cartridges have a much steeper and higher rise in pressure. It is hard to argue that firing the rifle cartridge isn't working the steel more than firing the shotgun cartridge. You may not have exceeded the elastic limits of the steel in your guns but there can be no denying that you are getting much closer to those limits than if you were just firing shotgun shells.

We understand the pressure/area differences between the rifle and shotgun shells and the effect on back thrust. Now consider that the rear of the small diameter rifle case distributes its high pressure back over just as small a portion of the action face. That little area takes the biggest hit. The area surrounding a shotgun's firing pin holes is the weakest area of the face. This area can be reinforced by installing hard steel bushings where the holes are located, but most people making shotgun-to-rifle conversions don't go through the extra work and expense to do this.

Firing overcharged loads, firing in extremely hot or cold environments, firing through a dirty/fouled bore, firing many shots in rapid succession, and all kinds of other situations will subject a firearm to extra stresses. All guns are "overbuilt" to provide a margin of safety for these types of extreme conditions and, of course, some firearms are "overbuilt" more than others. Converting a gun built to fire 11,500psi cartridges to one that will fire 42,000psi cartridges significantly reduces any margins of safety the manufacturer built into the gun. What you get will shoot --- but so will a zip gun made from a piece of galvanized pipe with a cap screwed over the end. The whole discussion boils down to this: What level of risk are you willing to accept?

Grenadier

--------------------
~


Post Extras: Print Post   Remind Me!   Notify Moderator  
Grenadier
.375 member


Reged: 20/02/08
Posts: 570
Loc: North of the Columbia, USA
Re: Proof loads [Re: Sarg]
      #97919 - 29/02/08 05:14 AM

Sarg,

With sincere respect, the original post was regarding "converting a Beretta 411 12 ga SxS into a double rifle in .444 Marlin"

Grenadier

--------------------
~


Post Extras: Print Post   Remind Me!   Notify Moderator  
Grenadier
.375 member


Reged: 20/02/08
Posts: 570
Loc: North of the Columbia, USA
Re: Proof loads [Re: Bramble]
      #97922 - 29/02/08 05:43 AM

Bramble,

Well, I sure didn't want to ruffle anyone's feathers and I never intended to do any "scaremongering".

If you are a professional that bills out at £75.00 PH and you put 100 hours into a conversion then, obviously, your conversions are not the type I was referring to. Regarding "cheap conversions": I still stand by what I said about them. There are many people out there that think you can just solder some sleeves into shotgun barrels, install rifle sights, and thereby magically convert a shotgun into a rifle. My hat is off to you for doing it the proper way.

For what it's worth, £75.00 for 100 hours is about $15,000US. Add that to the cost of a suitable shotgun to build the rifle on and you have enough in the USA to buy a "factory made" double rifle on the used market. You can even pick up some new Euro double rifles for less than that.

Grenadier

--------------------
~


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bramble
.375 member


Reged: 29/07/06
Posts: 950
Loc: England
Re: Proof loads [Re: Grenadier]
      #97927 - 29/02/08 08:06 AM

Grenadier

I appologise and I have gone back and deleted my post.

In hindsight I am un-necessaraly peevish tonight, it has been a long week.

The thrust ( no pun intended) of my argument remains. I have a 4xx series Beretta which is in the process of becoming a .470NE. Having examined the action carefully I have no quams about its ability to cope. 444 would be a breeze.
There is no corrolation between the proof pressure of a shotgun action with barrels and the strength same action with rifle barrels and its subsiquent re-proof pressure.

I don't do anything of this nature without serious consideration.
Please see the threads of mine on the .450#2 and 9.3 takedown.

Yes I have $15,000 in that gun in labour alone, the barrels were a further $800, action $1200. etc etc.

But that is the point, it is not a factory built gun, it is hand built.
I could afford to buy one, I just don't want to.
Without departing too far into some mystical BS I really do think that you can pick up a hand made item, gun, furniture, knife etc and somehow it is different to the product of a factory.

I do not for a moment ignore that there are some people that do some silly things and I am one of the first santmonious gits to point it out. But IMHO this is not one of them.

Regards


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sarg
.400 member


Reged: 20/01/07
Posts: 1141
Loc: New Zealand Australia South A...
Re: Proof loads [Re: Bramble]
      #97929 - 29/02/08 08:22 AM

I say guys ! it is I who had wrong end eh!
Sorry, I ment beleg2 who asked on his rifle not the 2005 start post !

Thanks

--------------------
No poor bastard ever won a war by dying for his country. He won it by making other bastards die for their country.

- General George S. Patton


Post Extras: Print Post   Remind Me!   Notify Moderator  
Grenadier
.375 member


Reged: 20/02/08
Posts: 570
Loc: North of the Columbia, USA
Re: Proof loads [Re: Bramble]
      #100035 - 23/03/08 09:09 AM

Here is the kind of conversion I was talking about:


http://www.gunbroker.com/Auction/ViewItem.asp?Item=95344942

--------------------
~


Post Extras: Print Post   Remind Me!   Notify Moderator  
450_366
.400 member


Reged: 17/01/07
Posts: 1068
Loc: Sweden, west-coast.
Re: Proof loads [Re: Grenadier]
      #107093 - 09/06/08 11:09 PM

I dont now if Searcy reproofs his guns, but if he did or sent it to a proof house wouldnt it be ok then?
In the old days they build doubles,combos and shotguns on the same actions, are these also dangerus?

--------------------
Andreas

"Yeas it kicks like a mule he said, but always remember that its much worse standing on the other end"


Post Extras: Print Post   Remind Me!   Notify Moderator  
4seventyModerator
Sponsor


Reged: 07/05/03
Posts: 2134
Loc: Queensland Australia
Re: Proof loads [Re: Bramble]
      #110150 - 21/07/08 05:04 PM

Quote:

a Ruger O/U which is not a great shotgun base to begin with




Bramble,
I'm not trying to start any trouble, but what are your reasons for disliking the Red Label action for conversion?
No grief here, just interested to know your opinion.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bramble
.375 member


Reged: 29/07/06
Posts: 950
Loc: England
Re: Proof loads [Re: 4seventy]
      #110183 - 22/07/08 11:18 AM

It won't start trouble Alan, it is only my opinion.

My reasons are that:
I don't like the bolting arrangment.
It has inertia cocking of the second barrel.
It is an investment cast SS action, not a forging.
It is light for caliber (7 1/2 lbs 12 guage)
I have a predudiced view that although the American firearms industry has made some superb products over the years, shotguns are not one of these.

Best Regards


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tatume
.400 member


Reged: 09/06/07
Posts: 1084
Loc: Gloucester, Va USA
Re: Proof loads [Re: Bramble]
      #110203 - 22/07/08 08:49 PM

Quote:

what are your reasons for disliking the Red Label action for conversion?



Quote:

It is an investment cast SS action, not a forging.



Bill Ruger made a strong case for his claim that investment-cast gun parts are superior to forgings.
After several decades of using Ruger products in some very intense chamberings and long, hard use,
I have never seen a Ruger casting fail. Machined forgings often look more classey, but I don't believe
that quality investment castings are mechanically inferior.

Take care, Tom


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bramble
.375 member


Reged: 29/07/06
Posts: 950
Loc: England
Re: Proof loads [Re: Tatume]
      #110240 - 23/07/08 06:49 AM

Hi Tom

yep it could very well be. It is only my predudice after all.

But consider this, for as long as I can remember whenever we want to get real horsepower out of an engine one of the first things that needs replacing is the cast crank with a forged item, same with the con rods.

Are Ruger castings good enough for their origional purpose. I have no doubt whatsoever that they are. But forging does realign the molecular structure of the steel and toughens the component.
When we look at conversions we are stressing the actions beyond their design limits and I just like an added margin.
BH in his article about his nice Red lable 45-70 conversion says himself that he sticks to low end loads. These then are far below NE loads.

Regards


Post Extras: Print Post   Remind Me!   Notify Moderator  
Birdhunter50
.375 member


Reged: 03/06/07
Posts: 811
Loc: Iowa,U.S.A.
Re: Proof loads [Re: Bramble]
      #110248 - 23/07/08 09:51 AM

One of the biggest problems with converting a shotgun to any rifle caliber is that somewhere out there is a nitwit just waiting to cram one of his hotloaded "Homeloads" into your nicely converted rifle, just because it will fit in the chamber. That is the reason that all of these need to be marked and hopefully built to hold up to ANY factory loads that are available. This is also why, for years any 45/70 loads that could be bought in any hardware store, were largely downloaded, because there were many weak 45/70's still out there that could blow with a modern, hotter loading.
444's are loaded quite a bit hotter than what I load in the converted 45/70's.
I know of one nut here locally that almost blew up his Marlin 444 with overloaded handloads. He was using a bullet that was way overweight and then added more fast powder to offset for the heavier bullets. I went out to see him one Saturday morning and found him filing .100 inch off the ends of his cases so he could crimp the heavier bullets. Left full length, they wouldn't chamber in his gun! Some people could blow up ANY gun if left to their own devices long enough. Bob H.


Post Extras: Print Post   Remind Me!   Notify Moderator  
450_366
.400 member


Reged: 17/01/07
Posts: 1068
Loc: Sweden, west-coast.
Re: Proof loads [Re: Tatume]
      #110371 - 25/07/08 04:00 AM

Did anyone see the mythbuster episode where they shot a s/s under water? That one did crack nicely, dont now the make but perhaps anyone here does.

--------------------
Andreas

"Yeas it kicks like a mule he said, but always remember that its much worse standing on the other end"


Post Extras: Print Post   Remind Me!   Notify Moderator  
9.3x57
.416 member


Reged: 22/04/07
Posts: 4713
Loc: Idaho
Re: Proof loads [Re: Tatume]
      #110388 - 25/07/08 11:44 AM

Quote:

Quote:

what are your reasons for disliking the Red Label action for conversion?



Quote:

It is an investment cast SS action, not a forging.



Bill Ruger made a strong case for his claim that investment-cast gun parts are superior to forgings.
After several decades of using Ruger products in some very intense chamberings and long, hard use,
I have never seen a Ruger casting fail. Machined forgings often look more classey, but I don't believe that quality investment castings are mechanically inferior.

Take care, Tom




Maybe this is the place to ask...

Some time ago I flattened a Ruger bolt handle as I like a flat bolt handle, being a lefty with the gun a righty it makes for easier manipulation and less cramping agains the scope when reaching over.

Anyway, there was a large occlusion in the center of the handle knob. It was unsightly so I drilled it out and made a ring-type bolt handle knob.

But...this gave me pause for thought.

How do they check for such in the lugs?

--------------------
What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?


Post Extras: Print Post   Remind Me!   Notify Moderator  
Kaimiloa
.224 member


Reged: 12/03/09
Posts: 37
Loc: Arizona, USA
Re: Proof loads [Re: Peterb]
      #132491 - 16/04/09 11:50 AM

Fred (Doublegunfan) and all,
This is such a great thread that it deserves a bit of new life I think. A lot of thoughts are swimming around now, so bear with me if this post gets long. Obviously, all those who read the whole three pages of the thread can see the considerable controversy around proofing. My friends in England absolutely swear by the necessity of their Proof Houses (not the mention the English proof law) whereas I think some of the English customs that prevail with today's proofing are arguably not good.

In the above thread is eyewitness coverage submitted by Bramble of some proofings at the London Proof House in early 2007.He wrote:
"I should like to add to this thread my experiences from the London proof house last week.

There are apparently three methods.

If the cartridge is current and common, they may have an assembled proof load in hand.

For my .450#2 they did not and I was asked to bring primed cases and heads into which they were going to assemble a proof load in blackpowder. However they only do this with lead bullets.

When they discovered that I had Woodleigh solids they decided to use my service load which was near maximum and they took the cases and oiled them liberally before firing the rifle.

The rifle was fired with the foreend detached.

Both barrels were loaded alough they were fired one by one.

The examination before and after was visual and physical. Checking that the rifle was on face, examining the bore and chamber.

Immediatly after firing the technicion removed the rifle from the chamber and before opening it held the breach up to the light to check for any gap opening between the barrels and the action face. He then opened the rifle and removed and examined the cartridges remarking on the ammount of primer extrusion indicating the pressure levels. Both primers were volcanic in extrusion and one had a burr forced up that I could remove with a thumb nail. He examined the chambers and the exterior of the barrels. No measuring equiptment was used.

He did remark to me that a similar process had knocked the .600 from a major manufacturer off the face just a couple of weeks earlier.

My rifle was stamped up as proofed to CIP limit of 3500 BAR.

My 6mm BR Norma Ruger #1 was proofed to the same method at the same time using my Lapua factory rounds again because of the relative rarity of the round."


Now it is my hope that somehow the Proof House has done CUP or Piesoelectric pressure testing using a myriad of oiled cartridges and somehow knows that this constitutes a reliable Proof for various cartridges suitable to stamp the gun as proofed to 3500 BAR. One BAR is about 14.5 pounds per square inch. So by oiling the cartridges, including B.P. ones apparently, we are to believe those guns are safe up to almost 51,000 psi!! I submit that very likely the pressure testing with oiled cartridges has not been done to any degree and so this proof stamping becomes almost ludicrous. If I am wrong I will gladly say so and apologize if offered good evidence.

That brings us back to the U.S. and many other place where fear of lawsuits produces very good and safe guns almost all the time. Many a gun and cartridge now in production started off as a likely wildcat - with many telling the experimenter they were crazy, about to blow themselves up, etc. Modern steels are WAY better than they were when rifles that we shoot with aplomb were made.

We also know that a good many shotgun actions have been converted to fire rifle cartridges and since I have heard of few accidents, its seems the daunting efforts to do this weed out a lot of dunces along the way. So let's just look at some "bottom lines" in this regard.

First off, tho not a DR builder, I am rather familiar with that breed, and would highly recommend that anyone contemplating building one, or having done so, get W. Ellis Brown's book "Building Double Rifles on Shotgun Actions" - 2nd Edition. Having spent a few hours with Mr. Brown in his shop, and read his book thoroughly, I can say that he is unusual in being quite humble about his experiences in this cloudy forest - and not at all afraid to tell of mishaps and serious mistakes. His descriptions of gun building are quite good and the photo back up is superb and profuse. See the last page for what cartridges he will, and WILL NOT, build a double rifle on. Notably, the .444 Marlin is in the low pressure category that he WILL build with.

If you are building with liners you can call the manufacturer and find out what steel is used and whether it is heat treated or whatever. Brown's book has a formula to help figure out needed breech thickness, so that may help. If the liner is intended to hold the pressure of something like the .444 on its own, the mfgr. should be able to tell you. The engineers at the steel-maker can tell you more about it too.

If you are using new barrels on the monobloc breech section of the shotgun, as Brown often does, again the barrel maker can tell you what the steel is and what it is designed to hold. You don't have to reinvent the wheel if it is already designed to hold a good bit more pressure than any standard load in the .444/.

That leaves the action strength, and again Brown tells you what to look for in a suitable SG action. Other SG actions are already being used here in the U.S. and elsewhere. Notably, it is the action strength and resistance to stretch that the London Proof House seems to be wanting to test with their oiled cartridge method.

I couldn't agree more with those who say you are playing with fire by picking out this or that smokeless powder and assuming that 7% above the max load will give you a 30% increase in pressure and therefore yield a suitable proof. This is generalizing dangerously - to say the least. Hodgdon is very progressive in the powder field now and a good talk with one of their senior ballistic techs MIGHT reveal a powder to use for a given cartridge which MIGHT yield linear pressure as you add a small percentage more than the max they list in their tables. This would be "off the record" of course, and very possibly you won't get the info. Again, fall back on what Brown does in his discussion on proofing, - if you feel you MUST proof despite researching all of the above.

If all else fails, and assuming you have built a decently strong gun, it is very likely safe to just fill your .444 cases with 1.5F Swiss B.P., topped with a typical bullet for same, and have a happy life shooting your D.R.

Aloha, Ka'imiloa

--------------------
Few pleasures exceed restoring a nice old gun and returning it to shooting and hunting.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Huvius
.416 member


Reged: 04/11/07
Posts: 2741
Loc: Colorado
Re: Proof loads [Re: Kaimiloa]
      #132501 - 16/04/09 01:25 PM

This is a good thread to revisit once in a while.

A couple questions I keep thinking of are:

1. If you are going through the effort to build and regulate a double for your own personal use, why worry about using maximum loads? IMO, reduced loads are more fun anyway - think cowboy action shooting. Load well below the accepted max. and mark the barrels as such. Or load with BP which is fun too.

2. How does a drilling pass a visual inspection at a proofhouse if it is impossible to see if a gap exists between the barrel and the breechface? Particularly if the rifle (high pressure) barrel is on the bottom?

--------------------
He who lives in the past is doomed to enjoy it.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Bramble
.375 member


Reged: 29/07/06
Posts: 950
Loc: England
Re: Proof loads [Re: Huvius]
      #132528 - 16/04/09 07:30 PM

As an appendium to this old thread.

London Proof house have revised their methodology under the new Master.

All rifles are being proved with loads assembled in Birmingham. If no proof load exists then one has to wait until they obtain one.

I had to do this last month with 2 new .318WR

I am somewhat uneasy with the science. I am informed that a 10% powder overcharge on book maximum is being loaded. The technicians were unable to give me any further data. I did point out that increases in powder did not necessaraly give liniar increases in pressure. But these guys do not make the rules.

I was not present when the WR were fired my employee was. He tells me that the report was so loud when one of the rifles was fired that the technician was startled. The bolt on that rifle had to be hammered open.

I am not sure the new regeim is a step forward.

Regards


Post Extras: Print Post   Remind Me!   Notify Moderator  
450_366
.400 member


Reged: 17/01/07
Posts: 1068
Loc: Sweden, west-coast.
Re: Proof loads [Re: Bramble]
      #132530 - 16/04/09 07:59 PM

Wow, 10% more powder, thats much.

Makes one wonder how much pressure a 460Wby gives at another 10 grains ?

--------------------
Andreas

"Yeas it kicks like a mule he said, but always remember that its much worse standing on the other end"


Post Extras: Print Post   Remind Me!   Notify Moderator  
Huvius
.416 member


Reged: 04/11/07
Posts: 2741
Loc: Colorado
Re: Proof loads [Re: Bramble]
      #132542 - 16/04/09 11:09 PM

Quote:

The bolt on that rifle had to be hammered open.

I am not sure the new regeim is a step forward.





Bramble, Bramble, Bramble...
Of course it is a step forward - in restricting trade and taking more guns away from the British people!

As if the laws weren't restrictive enough, now imagine all of the firearms out there which will not pass the new proof process. I would not be willing to subject any of my doubles to this torture.

--------------------
He who lives in the past is doomed to enjoy it.


Post Extras: Print Post   Remind Me!   Notify Moderator  
9.3x57
.416 member


Reged: 22/04/07
Posts: 4713
Loc: Idaho
Re: Proof loads [Re: 450_366]
      #132543 - 16/04/09 11:18 PM

My opinion...

No insults are intended {except to the ballistic bureaucrats themselves, none of whom I believe are represented on this forum...}

I've stated in the past, the British Proof House methods demonstrated have never filled me with confidence and I believe they have always been more or less useless and merely supportive of an additional useless bureaucracy. We have no such bureaucracy and certainly do not need it, either. Of course, under the current Regime I can see it coming... No gun may be sold without first being sent...by the dealer selling it it the new owner...to the Washington DC United States Union Proof House. Such a gun once proofed must be stamped with the initials of the Attorney General Eric "Patriot Hanger" Holder...

As for "10% powder overcharge on book maximum", such proves the absolute worthlessness of such a coffee klatch of ballistic buffoons.

Such a policy assumes they rely on Nosler, Hornady, Vitavouri, Speer, Hodgdon, Alliant, Accurate, Mulwex, Somchem, etc to determine maximum for them? Good grief what a stupid rule. All of the bookwriters assert their maximums are maximum using the gun and specific components listed ONLY. In that sense, no such general, universal "overcharge on maximum" exists.

And more...take a revolver for example...{not that many revolvers are being "proofed" by the British Proof House...}. A "10% overcharge" with some loads would demonstrate a dangerous load under the best circumstances.

So, the question is begged...

If the Proof House Genius's damage or wreck a guy's gun due to poor SOP, are they legally liable, or can they merely charge any ole case with any ole charge of any ole powder, blow the dam thing to ribbons, puff their chests out and declare it to have been a loser from the start?

Personally, I trust the legal concept of "civil liability" more than a bureacracy any day of the week.

Yes, I am saying it...I trust lawyers more than bureacrats!!

--------------------
What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?


Post Extras: Print Post   Remind Me!   Notify Moderator  
Daryl_S
.577 member


Reged: 10/08/05
Posts: 17856
Loc: Beautiful British Columbia, Ca...
Re: Proof loads [Re: 9.3x57]
      #132548 - 17/04/09 12:07 AM

7%??? now 10% - Gads! Can you believe the stupidity? One would have thought such air-heads would have been removed from the gene pool eons ago.

Overloading with BP is virtually impossible to do in any case, unless the wrong grannulation is used - BUT with care, changing granulations can work in proof as can compression amounts - witness the .303's first loading, velocities and presssures generated - 70gr. of BP powder in a 45gr. case. But smokeless - 10% - Good Lord! They will create bombs - not get their 20% or whatever increase in pressure, but double pressure depending on the ctgs. Such are smokeless powders today. Oh well, glad this doesn't happen here.

Bordhunter50 - As to shortening cases to allow crimping bullets with cannelures in the wrong place - sometimes mandated by heavier than normal bullets, sometimes by merely having a bullet with a wrongly placed cannelure for a particualr repeating action - is normal handloading practise - in itself is not a bad thing - but not knowing what one is about with handloading IS a bad thing. .444 Marlins typically have 38" twists and will not stabilize bullets much heavier than 310gr. Those Marlins have a working pressure limit of about 44,000PSI and at that pressure limit, using the correct powder, can achieve 2,100+fps with that bullet, 2,200fps with a 300gr. To load at the limits in any ctg. one must know what one is doing.
Most don't. Witness the new English Proof Rules! 10% more powder --

BTW - Marlin themselves tested a M1895 .45/70 to 70,000psi, the bolt opened normally and the case fell from the chamber, indicating no excessive bolt thrust nor pressure exceeding the elasticity of the 'new' brass.

--------------------
Daryl


"a rifle without hammers, is like a Spaniel without ears" Edward VII


Post Extras: Print Post   Remind Me!   Notify Moderator  
KWK
.224 member


Reged: 28/02/04
Posts: 49
Loc: Illinois
Re: Proof loads [Re: Daryl_S]
      #163949 - 13/07/10 12:32 PM

Some here scoff at the idea of Birmingham using 10% more charge as a proof load. Certainly, this is not ideal; but with a quick look over Hodgdon and A-Square data, one finds a 10% charge increase can create a pressure increase of 20 to 50 percent, depending on the powder and cartridge. Proofs need 33 to 44 percent over pressure (SAAMI), so this is pretty good as far as rules of thumb go.

Similarly, using the data to compute K.E. rise compared to pressure rise indicates the German approach of requiring 25% more energy also seems to give suitable pressures, but on the high end of the proof range.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Daryl_S
.577 member


Reged: 10/08/05
Posts: 17856
Loc: Beautiful British Columbia, Ca...
Re: Proof loads [Re: KWK]
      #163997 - 14/07/10 12:44 AM

I agree in theory, but - merely increasing a charge of X powder by 10% and calling that 'OK' is not the way to do it for the private handloader.

Pressure equipment in a Lab is needed and that 'proof' load must be worked up to using such equipment. Much depends on the exact powder being used as some become unstable as pressure climbs above a certain level. This can cause pressure 'spikes'. Case capacity and shape come into the situation as well. Pressure spikes are to be avoided, but can happen with a very small increases in powder charge, below 10%.

Many smokeless powders do not react in a linear fashion and rules of thumb can get you into a world of hurt.

--------------------
Daryl


"a rifle without hammers, is like a Spaniel without ears" Edward VII


Post Extras: Print Post   Remind Me!   Notify Moderator  
KWK
.224 member


Reged: 28/02/04
Posts: 49
Loc: Illinois
Re: Proof loads [Re: Daryl_S]
      #164002 - 14/07/10 01:26 AM

For the handloader, I'm more comfortable with a 10% powder increase than I am with passing proof by visual inspection. Precise headspace gauges to detect any significant yielding are, I feel, more important than getting the pressure spot on.

I would, though, insist on chronographing the loads to be sure the fps indicates a fair rise in pressure. Looking over published load data, it appears fps rise gives you a much better indication of pressure rise than does charge increase.

Without question, both approaches are flawed, and I can cite examples of both not working as expected. Still, I think either is better than no proof load at all.

Beyond that, the handloader must resort to using strain gauges. The T/C Encore makes an excellent platform for such work.

If you can find a lab with a piezo barrel, send them cartridges each with a bit more powder than the previous in the series and have them tested in sequence until a certain pressure is reached.


Post Extras: Print Post   Remind Me!   Notify Moderator  
CraigK
.224 member


Reged: 16/11/10
Posts: 8
Loc: Johannesburg, South Africa
Re: Proof loads [Re: KWK]
      #171824 - 21/11/10 06:18 PM

This is an extremely interesting thread!

I am a member of the South African Proof House’s Technical Committee , the Standards generating body for Gunsmiths and South African Firearms Manufactures Forum as I would rather be part of the solution than have some “idiot” make a decision for me.

We defiantly have two camps regarding proof testing: Those in favour and those who think it is an outdated and archaic practice (with most of the firearm importers and dealers being in this camp).

In South Africa according to the Standards Act we are required by law submit all nitro firearms for proof testing at the Firearms Proof House at the South African Bureau of Standards (S.A.B.S.) in Pretoria. We have our own proofing standards but they are essentially an overwrite of the C.I.P. Standards (we are not members of C.I.P. though we have applied on numerous occasions to become members).

As a small manufacturer and gunsmith I am in favour of proof testing as our production runs are small or one offs and we do not have the luxury of qualifying the design as one would in say a military production or a large civilian production run (say like Remington would). I believe that all firearms that are built (or have had structural repairs, rebarrels, etc) should be proof tested as part of your quality control, it helps identify problems like occlusions in barrels, poor headspace, etc and helps ensure that you put out a safe, quality product.

There are many dealers, gunsmiths and individuals here who do not agree with me being in favour of proof testing and would love to have me “hung drawn and quartered” for being in favour of it. I am of the opinion that the primary reason they do not like it is that it adds costs and is inconvenient to do.

When we started manufacturing our muzzleloaders we wanted to submit them for a VOLENTARY superior proof along with our nitro firearms to the S.A.B.S. it created a massive negative wave from a certain sector of our firearm society as if I (an alleged well known and respected gunmaker) thought it was a good idea to proof test our muzzleloaders (not a current legal requirement) the powers that be (read South African Police’s Firearm Registry) would possibly consider amending our Standards Act to include the proof testing of new and used muzzleloaders.

The S.A.B.S. proof testing procedure is basically as follows:

• Undertake a visual inspection, including chamber and bore dimensions.
• Fire two proof cartridges (30% above maximum commercial). If they do not have proof cartridges they will add 10% more of the same powder to a cartridge or use a bullet that weighs 10% more.
• Fire a commercial cartridge
• Undertake a visual inspection, including chamber and bore dimensions.

If the firearm is still within the required specification they will apply their proof mark if not it is rejected. If the firearm is damaged or destroyed during proof testing bad luck you lose and if you feel they erred take them to court (been there done that).

As they, the S.A.B.S. feel it is imposable (?) to blow up a muzzleloader along with said negativity they have to date refused to voluntarily proof test our muzzleloaders, despite our Standards Act allowing for it as they claim not to have the expertise so we do a factory proof on them which comprises of the following:

• Visual inspection
• Fire a maximum recommended load e.g. 500 gr FFg and a patched 4 oz ball in the 4 bore
• Fire a proof load; 500 br FFg and a DOUBLE 4 oz ball in the 4 bore
• Fire a maximum recommended load e.g. 500 gr FFg and a patched 4 oz ball in the 4 bore
• Visual inspection

If the gun or rifle is still within specification we complete it.

This will always be a controversial topic but manufactures and gunsmiths do need to test their product and services in order to keep you the shooting public safe and themselves safe from the lawyers mentioned so I for one will always be in favour of proof testing.

--------------------
Life is too short to shoot ugly guns


Post Extras: Print Post   Remind Me!   Notify Moderator  
beleg2
.375 member


Reged: 15/08/07
Posts: 591
Loc: Bahía Blanca - Argentina
Re: Proof loads [Re: CraigK]
      #172237 - 28/11/10 11:15 PM

Thanks Craig for the info!
It is very intersting.
Im not an expert nor a gunmaker I have only made a few muzzleloadiers and I proof some of them.
Many years ago I made a 12 bore smoothbore rifle to be shot with double charge as hunters in Ceylon according to Baker. To proof it I shot the provitional beligium or british proof (IIRC) that is double powder charge with 1.33 lead (I used 7# shot).
I also made a 12 bore howdah pistol and also proof it the same way.
Both guns were underhammers.
Thank you very much.
Martin


Post Extras: Print Post   Remind Me!   Notify Moderator  
DoubleRifle999
.224 member


Reged: 06/02/12
Posts: 24
Loc: North Carolina, USA
Re: Proof loads [Re: beleg2]
      #210222 - 06/06/12 09:45 AM

I thought I would bring this one back up again---seems like I have done that a couple of times recently!!

Since I am in the beginning stages of a build (and maybe two..!!), this subject holds more than a passing interest for me. I have read the entire thread----and something seems to be missing from the discussion.

I won't argue the advisibility of using shotgun actions or whether "proofing" is necessary. I think it is a great idea and so will proceed with that in mind. Here is what strikes me as odd: If you are considering a proof load and are wondering how to proceed, why not just develop a proof load?? Purchase a couple of boxes of new factory ammunition from different manufacturers. Take one or two rounds from each box and package them for shipment to a ballistics laboratory--these will be your "controls." Include with them some prospective proof loads of your own (maybe start with two rounds at "book max" then two at +4 percent, two at +6, two at +8, two at +10.....) or some similar arrangement. Have these rounds pressure tested by the lab. It will then be VERY easy to arrive at a proper "proof" load as required by the proof houses. No guessing, problem solved.

We know the parameters for proof (as published by the proof houses), we know what the manuals indicate as "max loads" and what that means (as evidenced by the manuals themselves), we know the design pressure parameters of the cartridges (as published by SAAMI or Birmingham or whoever..??), Soooo.....it seems a simple matter to load up a few rounds and have them pressure tested to determine a load that falls within the proof parameters of the proof houses. Yes..???

It goes without saying that you will need to record the load information of your test loads and mark them in a manner to identify them so the lab can record them properly on a data sheet. The only sticking point seems to be the availability of a ballistics laboratory. I know there are several (two or three..??) in the U.S. and all of the European proof houses can do this as well. I suspect there are labs "down under" as well and for that matter anywhere ammunition is developed and loaded.

Of course, I could be all wrong about this......

--------------------
...Howard...

Have tool will travel..

If you are not part of the solution,....You are part of the problem!


Post Extras: Print Post   Remind Me!   Notify Moderator  
Birdhunter50
.375 member


Reged: 03/06/07
Posts: 811
Loc: Iowa,U.S.A.
Re: Proof loads [Re: doublegunfan]
      #265717 - 30/05/15 10:38 PM

Doublegunfan,
According to some of these guys, self proofing your newly converted gun is impossible for an individual. I say that they don't have any experience with doing a proof test to begin with, in other words, they are prejudiced against any converted gun. You should carefully measure all the various parts and places they talk about in here, but in the end, it is the proof loads and the firing of them that will tell you if you have done a good job or not.
I have proofed many converted doubles, several of them on Beretta frames by the way, and here is how I do it. You need to figure out what is the heaviest bullet that is likely ever to be fired in your new gun. In other words the heaviest standard bullet for the caliber. Then you need to know what the load will be that you want to regulate it at, including the powder type and amount.
Taking the regulation load, you must make up a bullet, or buy one, that is 20 % heavier than the load you intend to use. It may be hard in some cases to come up with a bullet that is 20% heavier.
You don't need to worry about what the bullet is going to look like, it just has to fit the bore properly and be 20 over the regulation bullet weight. If necessary you can purchase a cheap aluminum bullet mold and re-cut it to make the bullet 20% overweight.
Next you need a proof testing fixture to hold the gun, I will try and enclose a picture of the one I use. Mine holds the gun upside down but that works out very well. I load both chambers and fire the first one with a long cord, then I move the cord over to the other trigger and fire it off.
I do two proof loads through each barrel, then two regulation loads, then I check out the gun. I have never had one fail yet, and some of them have been proofed for pretty heavy loads. Calibers proofed so far include a .600 special, 2 -.577's, 2 -.405 Winchesters, a .45-120-500, several 45-70's, several 20 gauge rifled slug guns, and 2 -12 gauge rifled slug guns.
None failed the proofing tests and all are still working and shooting at this time. I realize that 20% overload is more than many people use, but I feel that it is necessary to be sure the gun is sound. Good luck with your Beretta conversion. What do you think is the average working pressure of your load? You should be right about up towards the top end of what should be used in a conversion gun. I take it that your Beretta has no crossbolt in it, is that correct? The gun shown in the picture is actually clamped in sideways, it is a Ruger 20 gauge Red Label converted to a 45-70. Normal doubles are put into it upside down to test. I also mark the regulation load on the barrel flats so that everyone knows what it is proofed for. Bob



Post Extras: Print Post   Remind Me!   Notify Moderator  
Birdhunter50
.375 member


Reged: 03/06/07
Posts: 811
Loc: Iowa,U.S.A.
Re: Proof loads [Re: doublegunfan]
      #280569 - 08/04/16 10:55 PM

Doublegunfan,
How did the proof loading turn out on your Beretta 411? I am still interested in your project. I'm afraid we kind of hijacked your original thread with some of our own opinions. Did you proof the Beretta with 30% overloads for the 444? That is a great cartridge but I would be leery of shooting hot loads in it. What ever you end up using as a service load, you need to mark the barrel flats with the information. That may keep someone in the future from using something higher in pressure than what you proofed your gun for. Bob


Post Extras: Print Post   Remind Me!   Notify Moderator  
Wayne59
.375 member


Reged: 20/06/15
Posts: 859
Loc: Lagrange Ga. USA
Re: Proof loads [Re: Peterb]
      #280580 - 09/04/16 12:40 AM

I will probable make some people mad but I would be willing to wager that as many guns have blown up after they were proofed as guns that wern't proofed.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | >> (show all)



Extra information
0 registered and 42 anonymous users are browsing this forum.

Moderator:  CptCurl, 4seventy, mickey 

Print Topic

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled

Rating: ****
Topic views: 54361

Rate this topic

Jump to

Contact Us NitroExpress.com

Powered by UBB.threads™ 6.5.5


Home | Ezine | Forums | Links | Contact


Copyright 2003 to 2011 - all rights reserved