Home | Ezine | Forums | Links | Contact
NitroExpress.com: I Read All Of The OSR Thread, Time For The Machine Shop!

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


*** Enjoy NitroExpress.com? Participate and join in. ***
You are not logged in. [Login] Main Index · Search · Active Topics
New user · Who's Online · FAQ · Calendar

Double Rifles, Single Shots & Combinations >> Double Rifles
Previous topic Previous   View all topics Index   Next topic Next   Threaded Mode Threaded  

Pages: 1 | 2 | 3 | 4 | 5 | >> (show all)
Altamaha
.333 member


Reged: 29/12/08
Posts: 376
Loc: Washington State USA
I Read All Of The OSR Thread, Time For The Machine Shop!
      #144547 - 27/10/09 12:57 PM

First, a few disclaimers: I do not own a double rifle, have never shot one, will never own one (but I would like to!) and likely will never handle one or shoot one. I am just a poor old retired mechanic.

Two, Enough debating on the original OSR thread, so let us not get into another debate in this thread.

Three, I have read of OSR long ago, but it was not called this, just a short wording about using monometals in doubles. Have no idea of where I read of this, might have been in a magazine or a reloading manual.

Four, I have frequented machine shops most of my life (some 65 years) during this time I have tinkered with Mausers, and played with a few pressure testing systems.

So, here goes:

Is there merit in designing a test, using turned down barrels, equipped with Dr. Oehler's strain gauge system, taking careful measurements of the barrel outside diameter, firing a monometal bullet at standard velocity, then measuring the barrel for OSR? Maybe in conjunction with pressing monometals through a turned down barrel with a hydraulic press.

As I own a machine shop, the machining will be a snap. I have access to the Oehler System, the use would take some coordination, as the chap owning it is a distance away. I have used it in the past and have a M98 action set up as a single shot test receiver, mounted on a heavy recoil block.

So, double owners, what would a good test require in barrel thickness, bullet/cartridge combination, rifling type, etc? Maybe coating the barrel outside diameter before firing to reveal OSR for photography.

I am not saying I will be able to immediately jump into a project like this, due to other irons in the forge, but I should be able to work on this project this winter.

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


Reged: 22/04/07
Posts: 5504
Loc: United States
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: Altamaha]
      #144549 - 27/10/09 01:23 PM

Another BRAVO!

Can't wait to hear what you find out!

--------------------
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  
tinker
.416 member


Reged: 12/03/05
Posts: 4835
Loc: Nevada
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: Altamaha]
      #144553 - 27/10/09 02:50 PM

I second the bravo.


On barrel surface prep, go for the properly struck finish of a fine brit double rifle, with walls right about at .090" in the oiled and rust-blacked finish.

I haven't chapped a set of double rifle barrels yet, haven't handled a set of properly-chooched barrels showing OSR optical evidence either, but in my few 40 years of time around engineering and machine shops I've seen distinctly local surface finish affect on plenty of service parts that had been taken through the limits of their material's modulus of elasticity, affect that might measure in the fifty millionths neighborhood on the inspection table, but signs that something significant had occurred in the material.
The fine quality and finish of properly struck and blacked barrel steel would seem to me to be a good canvas for that kind of surface-finish affect.

From my experience, when the metal's locally lost it's nature it'll often somehow show at the surface.

Simply pushing mono solids through a barrel might not have the same effect as running them at the pace of normal internal ballistics.
Think of the difference some sweet-tart's ass might feel between a stroke with a buggy-whip and a good crisp snap with the same searing tip.
She'll likely turn and 'change her temper' to some extent at the crack, it'll definitely leave a mark that'll change the local landscape too.

Firing a cartridge in a rifle barrel is a very dynamic event.
Similar to the buggy-whip and temptress's ass analogy, when certain thresholds of energy delivery are crossed, there can be amazing consequences.

Just putting that out there for thought.





Cheers
Tinker

--------------------
--Self-Appointed Colonel, DRSS--



"It IS a dangerous game, and so named for a reason, and you can't play from the keyboard. " --Some Old Texan...

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


Reged: 10/04/08
Posts: 389
Loc: Tasmania, Australia
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: tinker]
      #144557 - 27/10/09 03:18 PM

Quote:

Think of the difference some sweet-tart's ass might feel between a stroke with a buggy-whip and a good crisp snap with the same searing tip.
She'll likely turn and 'change her temper' to some extent at the crack, it'll definitely leave a mark that'll change the local landscape too.
Firing a cartridge in a rifle barrel is a very dynamic event.
Similar to the buggy-whip and temptress's ass analogy, when certain thresholds of energy delivery are crossed, there can be amazing consequences.




Tinker,

Your comparison analogy has me in stitches; need to clean the coffee of the computer - again

All the very best

Alex

alexbeer.com

--------------------

Details matter!

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


Reged: 22/04/07
Posts: 5504
Loc: United States
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: alexbeer]
      #144565 - 27/10/09 05:59 PM

Tinker, not only hilarious, but exactly what we are looking for!

The gun I mean...

Your assessment is precisely what was discussed on the previous thread. Which "touch" the "ass" prefers, so-to-speak, now that, I do not know, but the principle you describe can be demonstrated in a variety of ways.

On a previous thread, 400ne suggested .078 as a barrel wall thickness of a thin-tubed gun. I'm not sure if it would matter or if that would be a significant detail, but such walls being much thinner than your .090, and assuming such barrels are safe, it would seem to me the thinner walls would give the best possible opportunity for a demonstration of OSR.

Correct?

I do not know what is considered the minimum threshold of safety on a, say, .458 barrel, but a related experiment would be a progressive reduction of barrel wall thickness combined with a firing to destruction of the barrel. I have no idea what diameter would allow for failure, but if the maker took the proper safety precautions it would be an interesting side experiment. Looked at another way, he obviously needs to be prepared {safety} for different demonstrations of material failure {not just relatively benign OSR} if he is going to turn the tubes down beyond known safe diameters.

--------------------
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  
gryphon
.450 member


Reged: 01/01/03
Posts: 5487
Loc: Sambar ground/Victoria/Austral...
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: 9.3x57]
      #144566 - 27/10/09 06:08 PM

the recent thread showing that incredibly high speed bullet photography?....would not that camera system show such an event and actually capture it?

--------------------
Get off the chair away from the desk and get out in the bush and enjoy life.

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


Reged: 28/08/07
Posts: 1031
Loc: Melbourne, Victoria, Australia
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: gryphon]
      #144573 - 27/10/09 08:09 PM

Someone who has Hatcher's Notebook: is it true he turned down the barrel of a Springfield to 1/16th inch over the chamber, yet still couldn't destroy it with a standard load?

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


Reged: 22/04/07
Posts: 5504
Loc: United States
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: Paul]
      #144575 - 27/10/09 08:50 PM

Quote:

Someone who has Hatcher's Notebook: is it true he turned down the barrel of a Springfield to 1/16th inch over the chamber, yet still couldn't destroy it with a standard load?



I'll quote it here, pages 201, 202 from "Hatcher's Notebook":

"The late Sir Charles Ross, whom I knew very well, had told me about his experiments on the thickness of barrels, and I had read some remarks by Newton on the same subject, but I couldn't get sufficiently authentic facts to satisfy me, so I collected some firsthand information by turning down a Springfield barrel to 1/8 inch wall thickness and firing it with regular and high pressure cartridges. As the results were not visible, I turned the barrel down so that it was only about 1/16 inch thick over the chamber. It held three regular service cartridges perfectly. I then put a 75,000 pound shot through which blew a piece out of the side, as can be seen in the photograph. As the thickness of the regular barrel at this point is 5/16 of an inch, it is plainly evident that the strength should be sufficient."

The photo is included in the book.

No mention of rifling forced to the outside of the barrel.

BTW: I think Gryphon's idea is brilliant! High speed photography would at least show the semi-fluid, vibratory, whipping nature of a barrel subjected to the effects of the firing of a shot tho if OSR is cumulative any single series of photos might not show it clearly.

--------------------
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 9.3x57 (27/10/09 08:54 PM)

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


Reged: 28/08/07
Posts: 1031
Loc: Melbourne, Victoria, Australia
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: 9.3x57]
      #144578 - 27/10/09 10:18 PM

Thanks 9.3, I'd read the Hatcher experiment referred to by a reviewer but never seen the reference.
- Paul

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


Reged: 22/04/07
Posts: 5504
Loc: United States
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: Paul]
      #144583 - 28/10/09 12:35 AM

Quote:

Thanks 9.3, I'd read the Hatcher experiment referred to by a reviewer but never seen the reference.
- Paul



You are welcome.

He mentions Newton, and I have a compendium of Newton's writings. Offhand I do not recall a specific experiment where he turned a barrel down but I'll look and see if I can find same in my material. If so, I'll post what he has to say.

--------------------
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  
Altamaha
.333 member


Reged: 29/12/08
Posts: 376
Loc: Washington State USA
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: 9.3x57]
      #144601 - 28/10/09 05:44 AM

I have Hatcher's, guess it is time to drag it off the shelf and blow the dust off.

I also have Howe's High Velocity writings, I will likewise take a look to see if anything showed up. I recall he worked with two diameter barrels, in which the bullet was swaged about half way down the barrel upon firing.

Safety, yep, when I proceed to turning a barrel down in stages until destruction, I will be behind a berm with a pull lanyard!

All we need is a financier with deep pockets for the high speed photography.

I am still savoring on a visual description of Tinker's illustration. Nice analogy.

And a well polished finish is a requirement for revealing any OSR, so this will go into my test requirements.

Keep the thoughts coming.

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


Reged: 01/01/03
Posts: 5487
Loc: Sambar ground/Victoria/Austral...
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: Altamaha]
      #144607 - 28/10/09 07:19 AM

All we need is a financier with deep pockets for the high speed photography.

Or maybe a photographer with an interest in rifles/guns or perhaps simply as a challenge to their expertise.

--------------------
Get off the chair away from the desk and get out in the bush and enjoy life.

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


Reged: 12/03/05
Posts: 4835
Loc: Nevada
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: gryphon]
      #144616 - 28/10/09 10:40 AM

The camera that captured the bullet-impact scenes is high-tech, high-buck kit.


Although the pressure of the ultra-liberal lead-bullet ban agenda might put us all in more of a 'need' for the final solution unleaded bullet design, I'm not going to sweat this one with any of my value-engineered to death (spare..!?) time.
North Fork and the guys down in SA seem to have for now answered the problem with a product that no one seems to be bitching about.

It's much more likely that I'd be found out in the machine shop with a dressage whip in one hand and a streaked and submissive strumpet's ass in front of my camera than huddled over a crapped-out double rifle with a bunch of smartypants hunters trying to get the lighting right for a photo opportunity on OSR damage.

That's something you CAN take to the bank.





Cheers
Tinker

--------------------
--Self-Appointed Colonel, DRSS--



"It IS a dangerous game, and so named for a reason, and you can't play from the keyboard. " --Some Old Texan...

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


Reged: 01/01/03
Posts: 5487
Loc: Sambar ground/Victoria/Austral...
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: tinker]
      #144619 - 28/10/09 12:55 PM

I will take the OSR photography over whipping some strumpets arse.

--------------------
Get off the chair away from the desk and get out in the bush and enjoy life.

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


Reged: 29/12/08
Posts: 376
Loc: Washington State USA
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: gryphon]
      #144621 - 28/10/09 01:21 PM

This is the second time I have dropped off the chair after reading Tinker's postings!!!!!

You need to go live and beat out Leno. No contest.

Anyway, I have several boxes of Jensen 250 gr 338 bullets, they have the small turned rings like the current North forks. Neat bullets, push them high and still have fine accuracy. Not made anymore, so I use them only for the serious elk hunting.

Am I wrong, but did not Jensen turn into North Fork????

My test proposal is just an academic exercise to see if I can duplicate OSR. Something fun to do when the snow is 3 feet deep and outdoor activities come to a halt. Fire up the shop wood stove, oil the lathe, and make chips!

Back to reality, for those owning a OSR barrel, at what point along the barrel is OSR first noticable? What is the bore diameter and wall thickness at the start of OSR? Does OSR gradualy start and become worse as we get closer to the muzzle? What is the wall thickness at the muzzle?

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


Reged: 23/11/03
Posts: 2397
Loc: Retired in Oklahoma
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: Altamaha]
      #144623 - 28/10/09 02:10 PM

Casio makes a series of high speed cameras the have the capability of recording at 1200 FPS..would that be fast enough?

Here is a sample of frame capture from a Casio camera.


3/5 scale model of Paixhans 500kg Monster mortar as 11 inch diameter projectile leaves the barrel.

Don't know if the camera would catch the bullet going down a thin barrel. It might be just a little to slow or not.

Bullet traveling at 1200 fps, might catch 2 frames of a 24 inch barrel, or one frame at 2400 fps in a 24 inch barrel

--------------------
DD, Ret.

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


Reged: 12/03/05
Posts: 4835
Loc: Nevada
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: DoubleD]
      #144628 - 28/10/09 03:48 PM

To get the kind of video quality seen in the recently posted high-speed video capture of bullet impacts, you'll need something with 1,000,000 frames per second refresh and capture rate. You'll also need to link that with a lighting system capable of running with it.

Although it's true you can get clear and crisp *still image* capture with relatively inexpensive equipment (really what's necessary is to get an enormous amount of light on the subject at exactly the moment in time necessary to 'show it' to your film or digital imaging media during an amazingly small amount of open aperture time) the real challenge is to get that to happen a million times a second.

The recently posted videos of bullet impact were likely shot on a serial string of cameras too. Even ultra hotrod equipment can only capture a certain number of frames before it either runs off the memory wagon or starts to cook.
At somewhere in the $200kUSD per camera price range, my guess is that there was a multi million dollar rig set up and running for the clips of each bullet path in that video shot by Werner Mehl from Kurzzeit

I'm thinking with that kind of system you'd be able to see the atomization of oil particles spraying off the barrel steel in a taurus cloud kind of effect.
Or not.

I wonder if there's such video on the web somewhere.





Cheers
Tinker

--------------------
--Self-Appointed Colonel, DRSS--



"It IS a dangerous game, and so named for a reason, and you can't play from the keyboard. " --Some Old Texan...

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


Reged: 17/01/07
Posts: 1068
Loc: Sweden, west-coast.
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: tinker]
      #144634 - 28/10/09 06:33 PM

I saw a sweet one, it had an enormus hard drive and did capture for about 10sek.
The thing was it did it all the time, when you had a decent capture, you pressed stop and you got the last 10sek. on the drive.

Price, didnt ask.

--------------------
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  
DarylS
.700 member


Reged: 10/08/05
Posts: 26513
Loc: Beautiful British Columbia, Ca...
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: 450_366]
      #144672 - 29/10/09 03:24 AM

I think tests such as this could be intriguing and helpful, but - the barrel steel would have to match the possible variety of the older guns in question - wouldn't it?

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


"a gun without hammers is like a Spaniel without ears" King George V

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


Reged: 29/12/08
Posts: 376
Loc: Washington State USA
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: DarylS]
      #144677 - 29/10/09 04:23 AM

Daryl brings up a point of which I am pondering. My thoughs are a recent 4140 barrel may not be suitable. But, if OSR showed up in a 4140 barrel, then we would be safe in assuming it would certainly be present in barrels made from older steels.

Anyone know of a source for barrel steel specs for the earlier doubles? Might the John Rigby Firm have an answer? I also wonder if the John Rigby Firm would have any interest in this project.

I always wanted to build a cut rifling machine, even have some designs, they are not that difficult to make. Now might be the time. Then I would be able to select a steel closely matched to the older barrel steels.

For Tinker, what do you think, is the most important factor Modulus of Elasticity, Ultimate Tensile Strength, or Elastic Limit?

Someone mentioned this subject was thrashed in the 1980's. Anyone have an article or a reference?

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


Reged: 12/03/05
Posts: 4835
Loc: Nevada
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: Altamaha]
      #144691 - 29/10/09 09:38 AM

Barrel material is not the only consideration.
The mechanical structure of a double rifle's (or combination/cape/vierling/drilling/etc) barrels (a weldment essentially) bring some specific and local restraint and stress-risers to the barrel tubes.

With ribs, wedges, etc, firmly (by design permanently) attached to the barrels, their expression of the 'donut wave' energy which occurs during the event phrase of internal ballistics is restrained for a portion of the barrel's radial section.
Furthermore, at the various seams (which are functionally stress-risers) there are distinct heat-effected zones.

Chew on that.

Via anecdotal study and discussion, the OSR syndrome appears to be *LOCALIZED* (along the helical path of rifling, in a helical banded pattern, duplicating the array of rifling) expression of excursions beyond elastic limit that print a pattern or optical effect on the exterior of the barrel surface.
This would definitely account for the transformation of the metal's characteristics (change of regulation, loss of accuracy...) WHILE maintaining relatively sound mechanical performance (the barrels don't completely bulge or blow) at the same time.

Acceleration is serious business.
We're talking Einstein shit here and those skinny barrel walls are seeing more and more force per area unit as the bullet cruises down the tube towards the muzzle.
More barrel tends to equal more velocity per given cartridge load!
That could have something to do with OSR showing up 'less near the breech, more near the muzzle' if that's the case.

If anyone here has a relationship with Werner Mehl or Kurzzeit (or wants to start one), that would be a good facility to consider for photo/video-documenting this phenomenon.
They already have the equipment.
It appears as if they have the interest in video-documenting the destruction of firearms and projectiles.

There is plenty of conviction, some available resource, and the possibility of some commercial industry participation to the point where the issue might even end up getting current technology in the pursuit of positively documenting this OSR business for those who will need 'picture-proof' of the 'Hard Monolithic Solid + (Classic or modern, *properly struck*) Double Rifle = OSR' recipe.
That might help settle the issue for another 20 years.







Cheers
Tinker

--------------------
--Self-Appointed Colonel, DRSS--



"It IS a dangerous game, and so named for a reason, and you can't play from the keyboard. " --Some Old Texan...

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


Reged: 01/01/03
Posts: 5487
Loc: Sambar ground/Victoria/Austral...
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: tinker]
      #144692 - 29/10/09 09:46 AM

And if Barnes or any other bullet manufacturer wants to prove that nothing untoward is happening by using their projectiles in DR`s then they would or should throw some money into the ring and fund a search for the truly definitive answer to absolutely prove this topic to any that question it.

Perhaps their shall I say silence so far on the matter to my knowledge is a matter for some conjecture!

--------------------
Get off the chair away from the desk and get out in the bush and enjoy life.

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


Reged: 06/01/03
Posts: 7244
Loc: Victoria, Australia
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: gryphon]
      #144693 - 29/10/09 09:53 AM



I think you may find also that the Shape / Sharpness of the Rifling has something to do with it.

Maybe, maybe not, but that could be just one factor in a whole load of factors.

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


Reged: 22/04/07
Posts: 5504
Loc: United States
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: tinker]
      #144695 - 29/10/09 10:20 AM

Quote:

commercial industry participation



Some are indeed working on it as we speak...

Stay tuned.

--------------------
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  
DarylS
.700 member


Reged: 10/08/05
Posts: 26513
Loc: Beautiful British Columbia, Ca...
Re: I Read All Of The OSR Thread, Time For The Machine Shop! [Re: 500Nitro]
      #144742 - 30/10/09 01:53 AM

Quote:



I think you may find also that the Shape / Sharpness of the Rifling has something to do with it.

Maybe, maybe not, but that could be just one factor in a whole load of factors.




I agree wholeheartedly, lots of questions. TKS guys.

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


"a gun without hammers is like a Spaniel without ears" King George V

Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | 5 | >> (show all)


Previous topic Previous   View all topics Index   Next topic Next   Threaded Mode Threaded  

Extra information
1 registered and 89 anonymous users are browsing this forum.

Moderator:  CptCurl 

Print Topic

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

Rating:
Topic views: 35716

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