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doublegunfan
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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


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Peterb
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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?

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Judson
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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.


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hoppdoc
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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.


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Daryl_S
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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


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hoppdoc
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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.

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

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


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Daryl_S
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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


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Bramble
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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


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308
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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)


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Raff
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Re: Proof loads [Re: 308]
      #71337 - 13/02/07 02:38 AM

www.gunproof.com

Birmingham Proof House, nice folks.

Raff

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larcher
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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

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"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."


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pistolchamp
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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.


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Bramble
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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


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9.3x57
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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)


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Marrakai
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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


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9.3x57
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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?


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Vinnie
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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


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9.3x57
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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?


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dnovo
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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

--------------------
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Vinnie
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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


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enfieldspares
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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.


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Rich
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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]

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400NitroExpress
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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)


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9.3x57
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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.

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bonanza
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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.


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