Pressure, the 6.5x55, the 7x57mm and old Mausers


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35 Whelen
December 28, 2011, 10:45 PM
It seems more and more there are discussions on this forum regarding the pressure limitations of older Mauser rifles. Lately, there have been a few discussion centered around the 1916 Mauser, the fact that many are available chambered in such relatively high pressure rounds as the .308 Winchester, and the supposed "facts" that this type Masuer actions is a ticking time bomb when so chambered.
The most regurgitated internet "fact" is that the 7x57mm cartridge is rated by SAAMI ( Sporting Arms and Ammunition Manufacturers' Institute ) at 46,000 CUP or about 51,000 PSI (There's no way to convert CUP to PSI or vice versa).

When I see these "facts" posted by supposedly informed individuals, I can't help but wonder how many people realize that the 7x57 is about 34 years older than SAAMI (Est. 1926) and how many realize that said cartridge is of European descent? In other words, pressures for the cartridge were established LONG before SAAMI was founded and decided that said 7x57mm cartridges loaded on American soil should be limited to 46,000 CUP. I also wonder how many Mauser and Mauser cartridge experts have heard of "CIP"?

CIP (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives )is the European equivalent of SAAMI. I'll not go into great detail about them as there's plenty of resources on the 'net. But to get to the point...

There's an excellent write-up, with non-internet references, on Wikipedia. Here's an excerpt(pay special attention to the last sentence):

"According to the official C.I.P. (http://www.thehighroad.org/wiki/Commission_Internationale_Permanente_pour_l%27Epreuve_des_Armes_%C3%A0_Feu_Portatives) guidelines the 7×57mm case can handle up to 390 MPa (56,564 psi) piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed (http://www.thehighroad.org/wiki/Proof_(firearms)) at 125% of this maximum C.I.P. pressure to certify for sale to consumers. By contrast, the American industry association SAAMI (http://www.thehighroad.org/wiki/SAAMI) specifies a lower maximum pressure of 46,000 CUP (http://www.thehighroad.org/wiki/Copper_units_of_pressure) or 51,000 psi.[4] (http://www.thehighroad.org/#cite_note-speer-3) Although this lower specification is in deference to the purportedly weaker actions of the older Mauser 93 and 95 rifles which are still in circulation,[4] (http://www.thehighroad.org/#cite_note-speer-3) this concern is misplaced, as the original ammunition developed for, and issued with, the M93 Spanish Mauser produced an average pressure of 50,370 CUP in those rifles.[5] (http://www.thehighroad.org/#cite_note-Whittemore-4) [6] (http://www.thehighroad.org/#cite_note-Cardenal-5)"

Hmm....kinda goes against the accepted internet forums info, eh?

Likewise, regarding the 6.5x55:

"The CIP (http://www.thehighroad.org/wiki/Commission_Internationale_Permanente_pour_l%27Epreuve_des_Armes_%C3%A0_Feu_Portatives) MAP for the 6.5 × 55 is 380 MPa (55000 PSI). SAAMI (http://www.thehighroad.org/wiki/SAAMI) MAP for this cartridge is 46,000 CUP (http://www.thehighroad.org/wiki/Copper_units_of_pressure) or 51000 PSI (http://www.thehighroad.org/wiki/Pounds_per_square_inch).[2] (http://www.thehighroad.org/#cite_note-accurate-1) All Swedish Mauser actions were proof-tested with a single 6.5 × 55mm proof load developing approximately 55,000 CUP (66,000 psi).[3] (http://www.thehighroad.org/#cite_note-2)"

Now, where did the rumor start that the older Mauser actions, ESPECIALLY the '96 Swedish Mauser, was designed for a 46,000 CUP cartridge?

For those of you that are handloaders, it doesn't take much research and extrapolation into the original loadings of either of these cartridges to realize that in order to obtain the ballistics they obtained, especially with the limited powders of 80 or so years ago, (remember, in the early part of the 20th Century, slow burning powders such as 4350's and 4831's had yet to be developed) the loads HAD to exceed SAAMI's 46,000 CUP.

Just a little food for thought...

35W

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gunner69
December 28, 2011, 11:30 PM
Great Write Up......

Most, if not ALL, European loads excede the power of the US makers for the same calibers. I own several of the older European calibers but don't load "hot" for them out of said safety issues. Do I think it will blow up my gun? No, but I am being "over" safe.

As long as I am not shooting +P loads I am really not worried much. I have hunted in Europe and used their ammo with narry a problem. Would I shoot their loads in the 100s or 1,000s? Probably not, but then I would not shoot +P ammo in my handgun for general/practice use either. The "good stuff" is for the kill.....

willypete
December 28, 2011, 11:47 PM
FWIW, I've read a lot of similar stuff regarding 6.5x55 Swede and have decided that my Carl Gustaf 38 will handle "modern" loads with slow burning powders (7828, 1000, etc.) with proper work ups. No problems so far, shooting both my reloads and European factory rounds (Lapua, Prvi).

PedalBiker
December 29, 2011, 12:20 AM
SAAMI is an organization set up by the manufacturers, not the consumers.

I think it's the fact that loads of 100 year old guns are still around, not the fact that 100 years ago (when they were new) they could handle full power loads.

Given the fact that most US manufacturers don't turn out a lot of modern arms with the metric cartridges, it just boils down to the numbers, many folks are buying ammo for really old guns.

If there were more modern arms chambered for the Xx57 and 6.5x55 would there be more full power ammo? Handloaders are ubiquitous and solve the problem themselves.

morcey2
December 29, 2011, 12:41 AM
The one that drives me nuts is the 8x57 SAAMI rating. 36000 CUP? Really? I know the reasoning behind it, but I've seen my share of M88 Commission rifles but I've never seen one that hasn't been converted to safely shoot .323 bullets. I'm not sure if any of the unsafe ones really existed! (I know they did, I don't think the numbers justify the solution.)

I shoot lots of Yugo surplus w/ 196 grain FMJBT bullets that are usually in the 2450 FPS range. Domestic Win/Fed/Rem loads are 170 Grain@2260/2350 FPS? Round Nose? Really? That's 30/30 ammo without the cool lever action. Prvi Partizan is slightly better, but not much. If you get the boxes marked "8mm Mauser", it's still pretty anemic, but at least it's a 196 grain pill moving at 2360. That's not too bad. The "8x57 IS" marked boxes are quite a bit better. But at least it's reloadable. I've got a couple more that I need to try: Gold Wolf, BVAC, Norma, S&B...

I'm building a 6.5x55 on a Spanish M93 action and it'll probably be loaded relatively mildly. The other one I'm working on right now is a 257 Roberts on a Yugo captured K98 receiver that I'm sure can handle full 257 Bob +P loads and then some. I also have a Mexican 1910 small ring 98 sporter in 7x57 that is currently my main deer/varmint/squirrel/clueless-teenage-boy-pursuing-my-daughter gun. I've probably got a little less headroom on that one with most off-the-shelf ammo, but it is a small ring, even if it is a 98.

Once I get fully equipped to reload all of them, I'll probably stop complaining. Maybe.. Hodgdon's website lists what looks like some pretty hot loads velocity-wise for all of the above, but they seem to have reasonable pressures.

I'll quit rambling now since my cold medicine seems to be kicking in. I can tell because the voices in my head start making less sense than normal.

Matt

R.W.Dale
December 29, 2011, 02:32 AM
None of which changes the fact that the rifles in question are OLD sometimes in questionable shape and tend to handle failures very poorly from the standpoint of the shooter.

At some point a limit has to be established for the sake of safety. Just because you don't agree with it doesn't mean its not there for a very good reason. After all in the case of the worst we're not talking about an inconvenience that merely messes up a $200 rifle. This is something that can KILL YOU. Even Paul Mauser himself lost an eye to pushing the envelope with HIS OWN DESIGNS

308 win is about as hot and has as much bolt thrust as anything on a .473" casehead. It is to this day almost at the limit for metallic cartridge pressures. I don't think anyone here will argue that a small ring Mauser is as strong as the platforms Winchester or the army had in mind when developing 7.62/308

Which brings us full circle if 308 was designed for much stronger actions then what is the limit for the small ring? Well its what the actual ballisticions at saami recommend vis-a-vis pressure ratings for the original chamberings. Any way you try to slice it the fact remains that the SAAMI piezo rating of 62k psi IS STILL HIGHER by 5000psi that even the highest cip piezo rating for 7x57mm.

All of which assumes the two bodies use the same calibration for their pressure trace



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Ignition Override
December 29, 2011, 02:52 AM
Was there no general correlation between military cup and Saami psi?

If not, then has 7.62 NATO ever been rated at about 58,000 max. average psi, or is the figure always much lower than commercial US .308. (62,000 psi or so)?

35 Whelen
December 29, 2011, 03:34 AM
None of which changes the fact that the rifles in question are OLD sometimes in questionable shape and tend to handle failures very poorly from the standpoint of the shooter.

At some point a limit has to be established for the sake of safety. Just because you don't agree with it doesn't mean its not there for a very good reason. After all in the case of the worst we're not talking about an inconvenience that merely messes up a $200 rifle. This is something that can KILL YOU. Even Paul Mauser himself lost an eye to pushing the envelope with HIS OWN DESIGNS

308 win is about as hot and has as much bolt thrust as anything on a .473" casehead. It is to this day almost at the limit for metallic cartridge pressures. I don't think anyone here will argue that a small ring Mauser is as strong as the platforms Winchester or the army had in mind when developing 7.62/308

Which brings us full circle if 308 was designed for much stronger actions then what is the limit for the small ring? Well its what the actual ballisticions at saami recommend vis-a-vis pressure ratings for the original chamberings


Wondered how long it'd take you to respond.

What prompted my research was the often mis-stated "these actions ('93, '94, '95, '96. etc.) were designed for cartridges that develop no more than 46,000 CUP" B.S. And sure enough, that statement is just that... recycled, internet B.S.

The .308 wasn't "designed" for or around the pressure limits of a particular action. If it was, then it'd been loaded to even higher pressures than it is. The .308 was simply designed as a shorter cartridge similar in power to the 30-06.

308 win is about as hot and has as much bolt thrust as anything on a .473" casehead. It is to this day almost at the limit for metallic cartridge pressures.

Have you taken the time to read this thread:7.62 NATO Pressure vs. commercial 308 Winchester (http://www.surplusrifleforum.com/viewtopic.php?f=76&t=39614)? Very interesting stuff with some good insight regarding actual chamber pressures of the .308 and 7.62x51. If you do take time to go there, read the entire thread, please. I think you'll find the .308 isn't the high pressure hot rod you think it is. And incidently, the .270 Winchester, first chambered in way back in 1925 (ironically, about the same time some of the actions in question were manufactured), has a maximum pressure of 65,000 PSI, or almost 5% more than the .308.

My Lyman 49th Edition has .308 loads listed in both CUP and PSI which is quite nice for making comparisons. While it is established that there is no direct conversion from PSI to CUP and back, by comparing CUP figures to PSI figures in loads using the exact same weight and brand of bullet, we can see something of a pattern. Generally speaking, Lyman maximum loads over all of the loads is 61,000-ish in PSI with the vast majority being under 60,000 and 51,000-ish in CUP with more loads UNDER 51,000 CUP than over. Hmmm....the CUP figures for the .308 are only slightly higher than those established by C.I.P. for the 6.5x55mm (55,000 PSI) and the '96 Mauser action, and within 1000 CUP of the C.I.P. established pressure for the 7x57mm (50,370 CUP).

It's late, and I'm going to bed and sleep peacefully knowing that my wife's 1916 in .308, with its proper headspace, is perfectly safe to shoot with commercial ammunition should the need arise.

35W

35 Whelen
December 29, 2011, 03:37 AM
Was there no general correlation between military cup and Saami psi?

If not, then has 7.62 NATO ever been rated at about 58,000 max. average psi, or is the figure always much lower than commercial US .308. (62,000 psi or so)?


No, no correlation. Please click the link in my post above and read the thread on the .308/7.62x51mm. Interesting, fact-filled stuff.

35W

R.W.Dale
December 29, 2011, 03:49 AM
Again none of which changes thr fact in the slightest that 308 is about 10% hotter than even the highest pressure military metric cip cartridge.

Yes 270 is slightly hottet and you know what it couldn't have been done till Winchester introduced the 54 made from Winchester proof steel.


When did you buy a set of headspace gauges?

At the end of the day I recommend to anyone to download for pre wwi guns. Because how safe they are isn't borne out by how well they handle a load when everything is perfect. But rather what the consequences are when something goes awry. A flawed case head or a blown primer on a Remington 700 is an attention getting event that can cause damage to the rifle that may need repair. That same event with a small ring Mauser will probably send you to the hospital and if not wearing eye protection will cost you your vision in at least one eye.

http://www.thehighroad.org/showthread.php?t=619628

http://m14forum.com/ammunition/99129-herters-308-steel-cased-ammo-failure-ruined-my-rifle.html

It does happen!

Is your wife's vision worth betting on some anonymous internet poster of unverified credibility or your own quest for positive reinforcement for something you're already doing against sound warnings? All I can say is I sincerely hope not.




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USSR
December 29, 2011, 08:06 AM
35 Whelen,

You are correct in your assessment that the 6.5x55 and 7x57 cartridges were not designed to be the low pressure rounds that American ammunition manufacturers now load them to. The loading down of these two cartridges is in deferrence to the weakest link in regards to available rifles in that chambering. In the case of the 6.5x55, the weak Norwegian Krag action chambered for that cartridge, and in the case of the 7x57, the occasional Remington Rolling Block rifle in that cartridge. There is nothing inherently weak about the case itself, and in a modern gun, both can be easily reloaded to the normal 60k psi pressure level that any modern bolt action can handle. With my 6.5x55 M70 Match Rifle, I can easily load 139 - 142gr Match bullets to 2950fps.

Don

R.W.Dale
December 29, 2011, 11:41 AM
35 Whelen,

You are correct in your assessment that the 6.5x55 and 7x57 cartridges were not designed to be the low pressure rounds that American ammunition manufacturers now load them to. The loading down of these two cartridges is in deferrence to the weakest link in regards to available rifles in that chambering. In the case of the 6.5x55, the weak Norwegian Krag action chambered for that cartridge, and in the case of the 7x57, the occasional Remington Rolling Block rifle in that cartridge. There is nothing inherently weak about the case itself, and in a modern gun, both can be easily reloaded to the normal 60k psi pressure level that any modern bolt action can handle. With my 6.5x55 M70 Match Rifle, I can easily load 139 - 142gr Match bullets to 2950fps.

Don

I agree with this. In a MODERN FIREARM there's no real reason every .473" case cartridge can't be loaded to 270 pressures. When I had a interatms markX in 7x57 I simply dispensed with the milktoast 7x57 data and loaded it like it was a 7mm08

But this isn't the point 35w is driving at. He's trying to justify hot loads in an OLD firearm just because higher pressure loadings exist.

Would you fire your match loads in an m96 Swedish Mauser for example?

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USSR
December 29, 2011, 11:59 AM
Would you fire your match loads in an m96 Swedish Mauser for example?

Only if the M96 was tied to a tire with a long string attached to the trigger.;)

Don

Gunnerboy
December 29, 2011, 12:10 PM
This is why i use Norma reloading standards rather than any American stuff for european rnds they actually have thier full potential when you load them the way they were meant to be

R.W.Dale
December 29, 2011, 12:20 PM
This is why i use Norma reloading standards rather than any American stuff for european rnds they actually have thier full potential when you load them the way they were meant to be

Speaking of Norma what is that pictured to the upper right of the screen on their reloading disclaimer page?

http://www.norma.cc/en/Ammunition-Academy/Loading-Data/

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Hummer70
December 29, 2011, 12:24 PM
I remember at Perry one year when Springfield Armory ( the real one in Springfield, Mass) had a display at Camp Perry. This would have been 57-60 time frame.
The took about two dozen old Mausers and placed the cleaning rods from them down in the barrel touching a live round and fired it under a proof hood.
Several barrels failed, no actions did.

I think it is Hatcher's Notebook about a guy that put a 30.06 chamber in a 6.5 Jap and fired it and action held. The guy that did it was a friend named Billie Merredith who was match pistol armorer at Quantico for Marine Team. He had a 30.06 reamer that was shot so he ground the pilot down to go in a 6.5 barrel and chambered it and fired it with a lanyard from behind a barrier. The barrel moved forward bout two threads but action held.

I have never heard of a catastrophic lug failure on a bolt gun that the heat treatment wasn't altered but I have heard of multiple barrel failures.

There was an article about a 1903 Springfield that blew up in the Rifleman back in 60s I think. Guy sued the gov't saying it was an unsafe rifle.

The rest of the story was told to me by the gov't expert witness who was a very good friend named Larry Moore. He said he got on the stand and the plaintiff's lawyer asked his name and position and then the screwed up, he next asked Larry to outline the development of the Springfield 1903 and Larry asked him if he wanted a brief overview or in depth survey. Lawyer screwed up again and said a brief overview would be fine.
Larry talked for five days on that one question and took nearly 500 pages of court transcript to type it up not including the charts, drawings etc. Lawyer stated he had no furthur questions. Jury was out about five minutes and came back and said the gov't did no wrong.

Dumb S&*T took a 03A3, heated receiver ring red to mount front scope block. Rear ring red to mount rear block. Then he put on a Griffin and Howe side mount after heating receiver red. Next he opened the bolt face and chambered it in 308 Norma Magnum and loaded it with a 30% overload. Went out and sighted it in and held.

He went hunting about 0 deg F and fired the first round at a deer, rifle let go, bolt went through guys face and tip of his nose wound up about even with his wisdon teeth and lived through it.

In Larry's testing prior to the lawsuit he duped what the guy did for loads and chambering but not heating the action and fired hundreds of rounds in testing and 03 held.

Small and medium case head rounds sustain massive plastic deformation about 90,000 pounds and it is estimated melt about 115,000.

I once did a malfunction investigation when I was with Army Small Cal Lab. M16 had let go expanding upper and lower receiver blowing mag into soldiers arm. The bolt and the barrel socket were fine. Extractor was gone. Couldn't see down the barrel and there was no case sent in. Took it to X ray and came back with a X ray of a 55 gr. FMJBT bullet nose to nose with a cleaning rod jag and patch on it. Barrel was not even visably swollen.

I read just the other day the M16 was a weak system. BS ! ! ! !

RevGeo
December 29, 2011, 12:30 PM
Pretty interesting stuff. I haven't shot a factory round in any of my rifles - excepting .22 rim fire of course - in many years. As a Mauser freak I have loaded for many of the older guns such as the '93, '94, '95, '96 and '98 (I wonder what happened in 1897?) using data from the usual sources. What the pressures are number-wise don't make much difference to the handloader as long as he/she watches for the usual high pressure signs, IMO.
I've loaded some stuff for a Swede carbine in 6.5x55 that was probably pushing 2900fps with no signs of excess pressure. Same with the 7mm and
8mm.
As 35W rightly points out, the cartridges are not inherently weak compared to more 'modern' rounds. And I personally think the '93 and '95 actions are plenty strong, even without the added locking lug of the '98.
As long as the rifle is in good shape, even at over 100 years of age, I have no problem loading them up while constantly watching for any signs of excess pressure.

The American rifleman who shoots factory ammo exclusively is stuck with rather anemic loads in the fine Mauser calibers, but at least the factory loads are a good source of brass:D.

George

35 Whelen
December 30, 2011, 03:17 AM
But this isn't the point 35w is driving at. He's trying to justify hot loads in an OLD firearm just because higher pressure loadings exist.

Wrong. I'm not trying to justify anything, rather put to rest some of the beauty parlor type, internet myths perpetuated by uninformed "experts" spouting undocumented, unverifiable, unreferenced facts. Myths such as "...the '93 Mauser was designed around a 46,000 CUP cartridge...":barf:

Yet in spite of the referenced material presented here including a test by H.P. White labs, some refuse to open their minds to the possibility that they might have been wrong or at least mislead.

And no Mr. Dale, I don't own a set of headspace guages. As an experienced handloader, I know the signs of excessive headspace without having to use a headspace gauge. (I've owned a few SMLE's that came to me with slightly excessive headspace...Neck size, son, neck size.) Since you evidently don't know the signs, shoot me a P.M. and I'll explain them to you. Then you can sell all your headspace guages and use the money to buy Xanex for when you shoot your Mausers. ;)

RevGeo summed it up VERY well. Read his post, follow his lead, and everything will be fine.

35W

P.S.- Mr. Dale, you reference a picture on the Norma website of a damaged '96 Mauser. Were you aware of the fact that Norma uses this action for load development?

From the Dec.2009/Jan.2010 Handloader Magazine:

"I set up a pressure barrel and fired a round. "Errr, sir, better not fire another." came from the technician. Pressure was a rather enthusiastic 81,000 psi. The equipment is only rated up to 65,200 psi! It says a lot for the old 1896 Swedish Mauser action that the pressure barrel was screwed into that it didn't let go and there was only a little stickiness when I opened the bolt."

The above statement was attributed to:

Dr. John Heath
D. Sc. Technical Support
Norma Precision

crazysccrmd
December 30, 2011, 03:35 AM
I shoot lots of Yugo surplus w/ 196 grain FMJBT bullets that are usually in the 2450 FPS range. Domestic Win/Fed/Rem loads are 170 Grain@2260/2350 FPS? Round Nose? Really? That's 30/30 ammo without the cool lever action. Prvi Partizan is slightly better, but not much. If you get the boxes marked "8mm Mauser", it's still pretty anemic, but at least it's a 196 grain pill moving at 2360. That's not too bad. The "8x57 IS" marked boxes are quite a bit better. But at least it's reloadable. I've got a couple more that I need to try: Gold Wolf, BVAC, Norma, S&B...

The Wolf Gold is pretty good, a 196gr SP moving about 2500fps and is PPU brass, might just be relabeled and not actually Wolf production. The S&B is good as well, 196gr SPCE (weird stepped design) moving about 2600fps. Both of their brass is reloadable but the Wolf (PPU) is much higher quality. It is easier to resize, prime and was closer to spec in length out of the box than the S&B.

willypete
December 30, 2011, 06:05 AM
Thank you, 35 Whelen. I love to see a logical argument backed up by facts, research, and citation. It's all the more enjoyable when it decisively pulls the rug out from tenuous internet rumors and those who proliferate them.

lonniemike
December 30, 2011, 12:07 PM
Dale and Whelen, Norma's opening reload page lists dozens of calibers. Where does Norma say that is a blow up of a 96 action or how can you tell. I can't see enough detail to determine the action type. And of course there are no details on the reason for the pictured rupture. It only states general reload precautions. Yes, I've seen pics posted of 96 actions that Norma used in the Swede development. And I wished that I'd copied them for show and tell. The Norma factory tour pics was shown sometime back by an unknown to me poster. Is Norma's Swede load hotter than the Swede mil load? Yes. Is Norma load as hot as the 264WinMag? No. Norma's load(about 50 KCUP) is about midway between the two(46 KCUPvs55 KCUP). AlltheBest

R.W.Dale
December 30, 2011, 12:44 PM
Thank you, 35 Whelen. I love to see a logical argument backed up by facts, research, and citation. It's all the more enjoyable when it decisively pulls the rug out from tenuous internet rumors and those who proliferate them.

Not once have I stated that the small ring was designed around a 40k psi cartridge.

What I'm trying to be is the voice of reason here. That just because 57k psi loads exist DOES NOT automatically make 62k psi OK too.

All you guys are doing is focusing on one aspect of shooting safety and pressing the limits on that. You're ignoring the inferior gas handling of this model. You're ignoring the age of the rifle and that your example has not had the same history as a few lab examples.

THIS ISNT A GAME! You or your loved ones can be blinded or killed. And for what? To proove some stupid point to an anymous internet poster.


And whelen with all due respect as an apparently more experienced handloader than you without headspace gauges or a micrometer case gauge YOU DONT KNOW SQUAT about the minute changes that will occour as headspace increases over very small increments over time. Especially if you neck size and let the shoulder push forward each time in compensation. Once those lugs get a little bit of free travel and slam into the races one too many times! Then the next thing you know you or your wife is shaking hands with Elvis.

BUT BY GOD at least you pointed out the obvious that 100years ago when these rifles were new. Back in a day when a certain fatalities rate per training hours was acceptable that they shot hotter loads in em then.

Loads that still are much milder than commercial 308

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Art Eatman
December 30, 2011, 01:19 PM
One factor in the factory loads for some cartridges is that the original rifles had only one locking lug. These were limited to approximately 40,000 psi. The 7x57mm is one such cartridge, as example, and the .30-40 Krag.

SlamFire1
December 30, 2011, 02:35 PM
According to the official C.I.P. guidelines the 7×57mm case can handle up to 390 MPa (56,564 psi) piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers. By contrast, the American industry association SAAMI specifies a lower maximum pressure of 46,000 CUP or 51,000 psi.[4] Although this lower specification is in deference to the purportedly weaker actions of the older Mauser 93 and 95 rifles which are still in circulation,[4] this concern is misplaced, as the original ammunition developed for, and issued with, the M93 Spanish Mauser produced an average pressure of 50,370 CUP in those rifles.[5] [6]"


This is a limitation of Wiki, Randy in Boise can edit it, and the more arcane the subject, the stupider can be the article:

For some reason people who spend 40 years learning everything they can about, say, the Peloponnesian War -- and indeed, advancing the body of human knowledge -- get all pissy when their contributions are edited away by Randy in Boise who heard somewhere that sword-wielding skeletons were involved. And they get downright irate when asked politely to engage in discourse with Randy until the sword-skeleton theory can be incorporated into the article without passing judgment.

Did anyone look at the references?

I did, the 1898 report was very interesting.

Pg 28, states that some of the Mauser Cartridges captured in Cuba had an initial velocity of 2200 fps.

When you get into Appendix 11, the Frankfort Arsenal contribution by Col Whittmore, you will find the weight of the Mauser projecticle is 173 grains.

Clearly we are reading about tests with the M1893 small ring rifle in 7mm Mauser and a service bullet of 173 grains.

When I read the Col’s section, he tested German and French ammunition in the “Mauser pressure gage” and the velocities he got were 2,166 and 2127 fps.

Col Whittmore than uses American powders to develop loads that give 2200 fps with German and French components. One of the pressure averages is 50, 370 pounds.

Using Bullseye, I can push a 173 grain 7mm bullet to 2200 fps and the pressures will be off the scale. :what: Does that prove the 1893 was “designed” to hold it?

No, it does not.

Col Whittmore is making the case to increase the pressures (38,800 psia) and velocity (2150 fps) of “our” service rifle ammunition to 50 K psia because the Mauser with its “double locking lug, is apparently no better able to resist the effects of such pressure as its ammunition develops than the US Magazine rifle, it is thought that the ballistic efficiency of our arm can be materially increased if a charge of powder be used giving a pressure about equal to that of the Mauser.

HELLO WORLD!! The Colonel is making the case to fire 50,000 pound loads in the 30-40 Krag!

Is Randy and his acolytes going to start making the pitch, that the plain carbon steel Krag is fine to rebarrel, shoot, with 50 Kpsia loads, because Col Whittmore said it is OK?

Col Whittmore should have stayed with cartridge manufacturing because he sure knows nothing about firearms design. :barf:

By the way, I looked up in my 48th edition Lyman handbook, for a 7mm Mauser with a 175 grain Jacketed, loads that develop around 2169, 2165 fps with various powders, the pressures are 33 Kpsia, 32.5 Kpsia.

If we are going to reverse engineer the M1893 rifle design limits from cartridge velocities,(which is half assed as all get out) the data does not support a design limit of 50 Kpsia. :rolleyes:

willypete
December 30, 2011, 03:14 PM
What I'm trying to be is the voice of reason here.

Quite frankly, you're not doing a very good job of it. You're coming across as fear-mongering and reactionary.

You or your loved ones can be blinded or killed.

And that ain't helping you.

And for what? To proove some stupid point to an anymous[sic] internet poster.

Um, what are you trying to do, again?

R.W.Dale
December 30, 2011, 03:24 PM
Quite frankly, you're not doing a very good job of it. You're coming across as fear-mongering and reactionary.



And that ain't helping you.



Um, what are you trying to do, again?

OK fair enough.

When things are unknown, unproven and the stakes of getting it wrong are high you err on the side of SAFETY

It may sound dramatic but when a small ring Mauser lets go the results are dramatic. They don't just blow the floorplate and lock up like a new firearm. They vent gas straight into your eye or flat out explode

posted via tapatalk using android.

crazysccrmd
December 30, 2011, 04:02 PM
I think what RW is trying to say is that not all of these older rifles are in the condition to fire full power high pressure loads anymore. Though most can handle it and keep going without problems at some point one will fail. Unlike the 98 actions that have a third locking lug to help stop the bolt from blowing backwards and the designed ability to vent gas away from the face the older ones do not. You just have to work up loads in your individual rifle and keep checking for signs of stress, not automatically assume the rifle can handle it.

R.W.Dale
December 30, 2011, 04:27 PM
I think what RW is trying to say is that not all of these older rifles are in the condition to fire full power high pressure loads anymore. Though most can handle it and keep going without problems at some point one will fail. Unlike the 98 actions that have a third locking lug to help stop the bolt from blowing backwards and the designed ability to vent gas away from the face the older ones do not. You just have to work up loads in your individual rifle and keep checking for signs of stress, not automatically assume the rifle can handle it.

Yes. And that involves maintaining some sort of pressure ceiling and checking checking and checking headspace.

And that doesn't involve putting your reading glasses on and holding a 4 or 5th firing neck sized only case at arms length underneath a lamp and proclaiming "looks good".

It means using a no go gauge and noting that bolt handle stops in the same place it did the last time you checked.

posted via tapatalk using android.

SlamFire1
December 30, 2011, 08:04 PM
The question of the true design parameters for the early Mausers is a difficult question. Inferences may be made from ammunition, from catalogs of the period. If you examine your Ludwig Olsen, that is what he did, the data on the 7X57 mm cartridge goes from 35 Kpsia up to 49 Kpsia.

The most true and reliable source would be Paul Mauser’s design notebooks. Those would be a primary source. Everything thing else becomes secondary.

There are lots of errors that creep on secondary, tertiary, subsequent editions. Just yesterday I was reading a book called “devil boats”. I was surprised to find, according to the book, that at the time of Pearl Harbor that the Navy was using the “M1904 Springfield”. I have never heard of a M1904 American service rifle, at least not before. You would think factory manuals would be a good reliable source, but then this week I was at a friend’s house. We were looking in his 1963 Chevy factory manual trying to find the specifications for clutch plate thickness. Could not find it. Even though the transmission was original to the vehicle, my friend had to figure out his own removal sequence, because it is not in the factory manual. The exploded diagram of the “not my transmission” was of no help at all.

I have written technical details of a design, passed it out, and seen how marketing and the Loggy’s, muck it up in their brochures and manuals.

I really doubt that Paul Mauser’s notebooks exist any more, I have no doubt that just like today’s arms designers, if you asked the Mauser Corporation, they would not tell you. They would have considered that proprietary, today, there is too much risk in telling people the design limits of firearms because reloaders will load to the limit and beyond.

Some of the members of SAAMI make and sell ammunition. That ammunition has to work in everyone’ rifle. If the ammunition blows up a rifle than there is the potential of a lawsuit. So when they determine standards, they have to analyze risk, profit and loss.

SAAMI has decided that making high pressure ammunition is too risky for these old military actions. Maybe they were too conservative, maybe they got it all wrong. But for the ammunition makers the risk represents real dollars, jobs, and they are not willing to accept the risk.

For those who are insistent on the quality of these actions and the pressure levels they can sustain, why don’t you put some skin in the game?

It is good that you are actually firing these things with modern ammunition. You are at least doing that. If your rifle blows up we will hear about it and if it does not break you can talk about it. But expand the discussion: make a commitment to the community. Personally guarantee that anyone who shoots these old rifles with modern high pressure ammunition, if the rifle breaks, you will buy them a new one. If they are injured, you will cover the costs.

Having real financial skin in the game will change this debate over night.

The supporters of these old actions can pool their money, post a bond, provide conditions and contact information, sit back confident in the future and with the satisfaction that they were right.

Money talks. ;)

willypete
December 30, 2011, 11:16 PM
R.W.Dale, your assumptions that people are ignorant or stupid are insulting, as is your insistence that bad data and emotional arguments take sway over numbers and destructive tests.

Again and again, it has been demonstrated that you are wrong, and yet you continue with your rhetoric. I guess what they say about arguing with idiots is true. I'm done with you. Go take up 35W on his offer to exchange your reloading tools for cash for anxiolytics; you'll be much happier and safer if you don't reload period. That's the safest course after all, right?

For those who are insistent on the quality of these actions and the pressure levels they can sustain, why don’t you put some skin in the game?

My skin is already "in the game." I'm the one firing the rifle.

The supporters of these old actions can pool their money, post a bond, provide conditions and contact information, sit back confident in the future and with the satisfaction that they were right.

Or we can just shoot the damn things and not play games of one-upmanship over the internet.

R.W.Dale
December 30, 2011, 11:25 PM
OK lets keep to the FACTS


308 Winchester = 62,000 psi

Hottest commercial 7x57 = 57,000 psi

What leads you to the conclusion that an additional 5000psi is completely safe ASSUMING 57k psi is?

posted via tapatalk using android.

35 Whelen
December 31, 2011, 03:46 AM
Honestly, I had become a little bored with the drivel, but now this is becoming humorous...sporting if you will!!

They don't just blow the floorplate and lock up like a new firearm. They vent gas straight into your eye or flat out explode

WOW...in a few minutes of research (far less time than I'll spend typing this post, hint, hint) and looking at my own 1916, since that seems to be the action in subject, I found a gas release port on each and evey rifle:

http://i60.photobucket.com/albums/h6/308Scout/Scout%20Rifle%20Project/Gasport.jpg

http://i60.photobucket.com/albums/h6/308Scout/Scout%20Rifle%20Project/GasPortf.jpg

http://i60.photobucket.com/albums/h6/308Scout/Scout%20Rifle%20Project/GasPorte.jpg

http://i60.photobucket.com/albums/h6/308Scout/Scout%20Rifle%20Project/GasPortd.jpg

http://i60.photobucket.com/albums/h6/308Scout/Scout%20Rifle%20Project/GasPortc.jpg

http://i60.photobucket.com/albums/h6/308Scout/Scout%20Rifle%20Project/GasPortb.jpg

http://i60.photobucket.com/albums/h6/308Scout/Scout%20Rifle%20Project/GasPorta.jpg

...and unless you mount a parascope, sideways with the ocular lense facing left over the front receiver ring, looks to me like it's going to be very difficult for a ruptured case head or a blown primer to "vent gas straight into your eye".

What leads you to the conclusion that an additional 5000psi is completely safe ASSUMING 57k psi is?

Going back to facts (FYI, facts are the opposite of conjecture which is synonymous with rectal extraction)

"In C.I.P. regulated countries every rifle cartridge combo has to be proofed (http://www.thehighroad.org/wiki/Proof_(firearms)) at 125% of this maximum C.I.P. pressure...."

That'd be a little over 70,000 PSI. What was it H.P. White proofed these rifles at....98,000? Hmm....

You know, if I don't stop reading these posts, I may be the one who needs the Xanex!!:D

35W

R.W.Dale
December 31, 2011, 04:39 AM
You really don't have a clue do you.

You think that just because there's a gas vent hole that in the event of a case failure all 60k psi worth of superheated gas will go out that little hole and the shooters hair wont even be ruffled.

Ever wonder why the cocking piece on a large ring Mauser is so different compared to a small ring?

Its because without the gas deflection flange provided by the large ring cocking piece and a couple of striker changes in the event of a case rupture superheated gas has just as easy a shot straight back along the bolt body or even through it to the shooters face as it does to make a 90 degree turn and all go out that vent hole.

The large gas flange at the rear of the Mauser bolt has been copied or reproduced in some way on modern rifle designs, but the gas deflecting step in the bolt shaft has been left out. The Mauser bolt has a step towards the rear of the bolt that mates with a step in the receiver which prevents the gases getting a straight shot at the shooter under the flange.

http://hunting.about.com/od/guns/l/aastboltsofCg.htm

Another safety feature of the Model 98 is the large gas shield at the front of the bolt sleeve to protect the firer’s eyes from hot gas and brass splinters in the event of a pierced primer or case-head separation. Oblong holes in the bottom of the bolt body serve the same purpose.


http://www.americanrifleman.org/m-articlepage.aspx?id=1938&cid=3


In addition, the M-98 incorporated gas-venting holes in the bolt body that direct gas downward into the magazine and a gas deflecting flange on the bolt sleeve to protect the user from a pierced primer sending back gas along the locking lug raceways. It is said that Paul Mauser’s losing his sight in one eye was the impetus for all the designed-in gas safety features.
http://www.chuckhawks.com/mauser_gewehr98.htm


To quote the wiki about the 98

"The action features two large gas relief holes and a gas shield on the bolt sleeve designed to protect the users head in case of a primer or cartridge rupture or detonation. When the action suffers a catastrophic failure these safety features deflect escaping gas and eventual debris away from the operator's face."

http://en.m.wikipedia.org/wiki/Gewehr_98

You also fail to fundamentally understand the reasons behind proof loads.

A proof load tells the manufacturer that if something goes wrong that rifle wont explode then for a single point event. IT DOES NOT Mean the firearm can be fed a steady diet of near proof loads and not eventually fail as with the case of a small ring in 308 win

posted via tapatalk using android.

SlamFire1
December 31, 2011, 07:46 AM
Even though the small ring Mausers have a gas vent, it is not particularly effective in blocking gas escape back into the action. As you can see in these pictures the magazine well has been expanded, the bolt stop is sprung, extractor and collar blown out of the action and the receiver ring split. This is one of those Spanish 308 Winchester conversions.

http://img.photobucket.com/albums/v479/SlamFire/Blowups/pix517853969.jpg

http://img.photobucket.com/albums/v479/SlamFire/Blowups/pix517854000.jpg

http://img.photobucket.com/albums/v479/SlamFire/Blowups/pix517853500.jpg

http://img.photobucket.com/albums/v479/SlamFire/Blowups/pix517853454.jpg

http://img.photobucket.com/albums/v479/SlamFire/Blowups/pix517854235.jpg

The M1903 has a similarly ineffective breeching system and later the “hatcher hole” was added. The hatcher hole is a gas vent on the left side of the receiver, same basic location as on the small ring mausers.

You might be able to see it in the pictures. This National Ordnance receiver was so soft that it developed excessive headspace and the cartridge ruptured. As you can see in the photographs gas escaped everywhere and the shooter was injured.

This shooter is still experiencing problems:

i was the guy who had the National Ordnance 03A3 blow up in my face. I like you am still pushing people away from those ticking time bombs they call rifles. I had one surgery after I last conversed with you. Had to have a tooth removed, piece of brass was blown into my nerve and the sun still burns my eyes from absorbing heat.

http://www.jouster.com/forums/showthread.php?t=2893


http://img.photobucket.com/albums/v479/SlamFire/Blowups/Blownoutleftsidestock.jpg

http://img.photobucket.com/albums/v479/SlamFire/Blowups/Blownouttriggerguard.jpg

http://img.photobucket.com/albums/v479/SlamFire/Blowups/Rightsideaction.jpg

http://img.photobucket.com/albums/v479/SlamFire/Blowups/bloodonsweatshirt.jpg

bobnob
December 31, 2011, 08:09 AM
I have a Berlin DWM Mauser manufactured in 1897, I am told its probably a Mauser 95 design, but its marked "MOD. MAUSER 1897".

It has been rebarreled in .308 Win. Was subject of a post on here some time ago.

I shot factory loads through it on and off for about 25 years, as well as a variety of handloads that were on the mild side.

My instincts tell me it is fine for the factory loads, however in deference to the age of it I feed it relatively mild handloads now. ie 150g bullets around 2700 fps or so, using 44g of AR2208 (Varget).

I imagine this would be as safe as you could reasonable expect. Any thoughts?

35 Whelen
December 31, 2011, 12:48 PM
I imagine this would be as safe as you could reasonable expect. Any thoughts?

I'll go ahead and answer for R.W. and SlamFire:

"Do NOT under any circumstance fire this rifle with any loads that develop chamber pressures exceeding that of the 22 Short rimfire. Doing so will blind you, blow both your hands and most of your toes off. Also, I read on another internet forum about a guy who did this very thing and from that point on, all his children were born naked!":D

My thoughts? You're doing exactly what I do with mine, except I don't shoot factory loads. Your load should be way below the real limits of these actions. My load of pulldown 4895 propels a 150 gr. Remington a shade over 2700 fps. If this load ruins my rifle, then I don't need it and I'll use it for a trotline weight.

By the way Slam, nice Mauser pictures, but I think you've already posted them. What's the deal with the blown up rifles and NO explanation, no story? Was it factory loads? Handloads? Possible bore obstruction? It's like your kids getting in trouble at school yet saying "I wasn't doing anything wrong!"

The one single rifle I personally witnessed blow up was a custom 25-06 built on a nice commercial '98 Mauser action. The old guy had fired several of his handloads (IMR-4831 & a 120 gr. Hornady as I recall) with no problems, then suddenly he's standing there with the buttstock, broken just behind the tang, in his right hand, and the remainder of the rifle in his left. Explanation? His never ending desire to run loads as hot as possible.
So, no, I KNOW the gas port won't handle all the pressure, but the gentleman was relatively unharmed save a small metal fragment in his face.

IT DOES NOT Mean the firearm can be fed a steady diet of near proof loads and not eventually fail as with the case of a small ring in 308 win

I don't where you got the idea that anyone here thinks the rifles in question can be fed a steady diet of "near proof loads".

35W

R.W.Dale
December 31, 2011, 02:15 PM
Well if proof loads are 70k psi and factory. 308 ammo generates 62k psi that's shooting ammo that's only 10% below a 125% proof load

That's awefully close and is in fact closer to proof loadings than it is hot 7x57 cip loading.

And if the KB you witnessed had been with a small ring Mauser the shooters injuries would have required immediate medical attention as per the safety improvements his 98 has compared to your small ring.

Any way you care to slice it factory 308 win is way overpressure compared to even the hottest 7x57 loadings

posted via tapatalk using android.

USSR
December 31, 2011, 02:40 PM
I'll go ahead and answer for R.W. and SlamFire:

"Do NOT under any circumstance fire this rifle with any loads that develop chamber pressures exceeding that of the 22 Short rimfire. Doing so will blind you, blow both your hands and most of your toes off. Also, I read on another internet forum about a guy who did this very thing and from that point on, all his children were born naked!"

A cheap shot, 35 Whelen.

...I KNOW the gas port won't handle all the pressure, but the gentleman was relatively unharmed save a small metal fragment in his face.

Oh, as long as it was just a small metal fragment.:rolleyes: Not using small ring Mausers for high pressure loads goes back to before most of us were born, so it's not like R.W. Dale and SlamFire are making this stuff up.

Don

R.W.Dale
December 31, 2011, 03:49 PM
So, no, I KNOW the gas port won't handle all the pressure,

apparently not till recently as evidenced by your previous statement of.. (bold added for emphasis)


WOW...in a few minutes of research (far less time than I'll spend typing this post, hint, hint) and looking at my own 1916, since that seems to be the action in subject, I found a gas release port on each and every rifle:


..and unless you mount a parascope, sideways with the ocular lense facing left over the front receiver ring, looks to me like it's going to be very difficult for a ruptured case head or a blown primer to "vent gas straight into your eye".

So where are we now

dont own headspace gauges

dont know what the rifles headspace is

found some higher then 50k psi 7x57 loads on the internet that still fall way short of 308 pressures

saw a k98 blow up where it protetected the shooter from injury with several key features your rifle lacks

proof loadings for the original chambering are only a few thousand PSI hotter than 308

please enlighten us as to how all these factors brings you to the conclusion that firing factory 62,000psi ammo in a small ring is OKAY

SlamFire1
January 1, 2012, 11:37 PM
Jerry Kunhausen’s book “Mauser Bolt Actions” discusses these early actions in several sections.

ON page 71, he states that M91-M96 receivers that he had tested had steels roughly equivalent to SAE 1020, 1025, 1030. He states one Spanish made receiver was below 1020. These steels are so low grade that today they are used for rebar.

Looking at data on Matweb, the low carbon steel used in these early receivers is not used for complicated parts, unheated it is used for rebar, if heat treated for medium duty shafts, studs, bolts and nuts. I did a composition search and found AISI 1117-1118 steel, which is similar in composition to Springfield Armory Class C steel used in the Krag's and in the M1903. I could not find something that was just carburized and quenched, which was the single heat treatment at Springfield and what early Mauser plain carbon receivers would have experienced. I found data for 1 inch round AISI 1118 mock carburized, reheated to 1450 F, quenched, tempered. This is similar to the M1903 double heat treatment. The Ultimate strength is 103,000 psi, yield 59,300 psi, elongation at break 19%. For something similar to WD2340 Nickel steel, which was used at Springfield in 1927, I found one inch round AISI 4820. For that material, mock carburized, 1450 F reheat, water quench, the ultimate strength was 163,000 psi and the yield strength was 120,000 psi, elongation at break 15%. Many modern receivers are made from 4140. For a 1 in round AISI 4140 Steel, normalized at 870°C (1600°F), reheated to 845°C (1550°F), oil quenched, 260°C (500°F) temper, ultimate strength 270,000 psi, yield 240,000 psi, elongation at break 11%


Just looking at the material properties, you can see how material technology improved as the century progressed.

Kunhausen makes the claim, on page 85, that the 7.62 mm CETME cartridges produce pressures in the 41,500 to 42,000 CUP range. No reference given and if you search on the web you will find statements that the 308 cartridges made for these actions had 130 grain bullets to reduce pressures.

Figure 79 shows a M93 receiver that the Spanish converted to 7.62mm CETME. The receiver lug surfaces are set back .009” from use.

This post from another forum has interesting data on these small ring Mausers: (emphasis mine)


http://www.surplusrifle.com/shooting2006/spanishmauserrevisited/index.asp

A substantial amount of information has been compiled concerning the safety and reliability of the Spanish built FR-7, FR-8, and Guardia Civil rifles. The FR-7 and Guardia Civil 1916 rifles are built on the 1893 pattern rifle. This particular design employs a two-lug bolt system, as opposed to the 1898/1943 model rifles adopted by the Spanish government.

The 1893 pattern is a small ring Mauser action, 1893 pattern, with the two-lug bolt system.The 1943 model employs the much-improved three-lug bolt system (two locking lugs and a non-bearing safety lug). The model 1943 is a large ring rifle that was originally chambered in 8X57. The FR-8 is a converted 1943 model. The FR-7 is constructed on the 1893 pattern. Many of both the 1893 pattern and 1898 pattern rifles were converted to the 7.62 x 51 mm NATO cartridge.

It should be noted here, that the small ring 1893 Mauser in 7 x 57 mm caliber was designed for a maximum chamber pressure of 46000 cup. The 7.62 x 51 mm NATO round topped with the standard 147 grain FMJ military ball bullet generates a maximum of 50,000 psi of chamber pressure.

The commercial .308 Winchester round topped with a 150-grain bullet generates an average working pressure of 52,000 cup. The .308 Winchester’s maximum pressure is limited to 55,200 cup, well above the pressure for which the 1893 pattern and the 1916 short rifle were designed. The 1898 type 1943 Mauser rifles are perfectly capable of withstanding the higher pressures of the 7.62 NATO cartridges. However, a prudent person would/should have this model Mauser and other military surplus weapons checked by a competent gunsmith using the appropriate testing methods prior to firing them.

I currently own both an FR-7 and a Guardia Civil rifle (1916 Short Rifle). Both appeared in excellent condition when purchased. However, upon having them examined by two local Mauser experts, Cliff and Charles Houston of St. Petersburg, Florida, they found that the headspace was beyond what is considered to be a normal range. This was determined by the use of field and go/no gauges.

An additional portion of their examination of these two rifles concerns the steel used in the construction of the 1893 pattern receivers of these rifles. The Spanish steel was of an inferior grade (as compared to the original German produced models). Unfortunately, this was a common practice of Spanish arsenal made rifles. Apparently they had a propensity for disregarding generally accepted principals of metallurgy. The hardness of the two receivers was determined through the use of a low tech, but thoroughly reliable device called a Scleroscope. This simple, but reliable device has been in use in numerous types machining and manufacturing industries for many years. It consists of a glass cylinder marked with a Rockwell “C” scale, and a ¼ inch alloy ball of known hardness. The cylinder is placed over the receiver, and the ball released. The level to which the ball rebounds to is noted on the scale. Upon comparing the level to which the ball rebounded when compared to dropping the ball on a piece of hardened tool steel it is readily determined that the steel used in the manufacture of these two rifles is of an inferior (softer) grade as opposed to rifles manufactured by German or Belgium companies.

An additional attribute of the Scleroscope lies in the fact that this device does not penetrate the surface of the weapon being evaluated. Other devices penetrate the surface, and therefore will mar the finish on the rifle being evaluated. These other devices, while undoubtedly more definitive, are more cumbersome to use, and substantially more costly. The Scleroscope is simple to use for the average person, is very portable, and requires no batteries or sophisticated knowledge for its use.

The combination of a two-lug bolt system, a soft steel receiver, and a rifle chambered and rebarreled for a cartridge that generates substantially higher chamber pressures than what the original design was meant for can be a prescription for disaster.

Unfortunately, many of these rifles that were re-chambered to 7.62 NATO caliber and marketed and advertised for sale in national publications as safe for use with both 7.62 NATO ammunition and .308 Winchester, with scant warning to the consumer. Therefore, caveat emptor (buyer beware) is the watchword!!!

SlamFire1
January 4, 2012, 06:58 PM
Another post on the these old M93 type actions.


http://www.thehighroad.org/showpost.php?p=7822362&postcount=12

I recommend... ________________________________________
that you honorably retire the rifle.
My experience with the Spanish '93-type actions is that they are not suitable for rebarreling to any modern cartridge at all.
They are all soft (many years ago, I watched an old gunsmith squash one in simply tightening his action wrench onto it. When he noticed that the barrel shank wouldn't thread back into the action, and realized why, he simply took the receiver out of the wrench, laid it on his bench and smacked it with a big brass hammer until he could screw the barrel back in).
With pressures higher than about 40 KPSI (virtually all modern CF rifle cartridges), the locking lugs will set-back into their seats very quickly, increasing headspace until the bolt becomes hard to open and case heads separate. Several years ago, a customer (and friend) decided he'd like to make up a 7.62x39 rifle on just such a '93 Spanish action. I couldn't talk him out of it, so made and fitted a barrel for him. In shooting about 200 rounds of Wolf ammunition, it battered itself into just the state I described above.
Just my recommendation, but not based on hearsay.

SlamFire1
January 4, 2012, 07:28 PM
Found the pictures but not the story. Looks like the event created a new gas vent hole.

I think this is a Swedish action from the gas port hole on the bolt.

http://img.photobucket.com/albums/v479/SlamFire/Blowups/BlownUpsmallringmauser1.jpg


http://img.photobucket.com/albums/v479/SlamFire/Blowups/BlownUpsmallringmauser5.jpg


http://img.photobucket.com/albums/v479/SlamFire/Blowups/BlownUpsmallringmauser5.jpg

http://img.photobucket.com/albums/v479/SlamFire/Blowups/BlownUpsmallringmauser3.jpg


http://img.photobucket.com/albums/v479/SlamFire/Blowups/BlownUpsmallringmauser4.jpg

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