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barker2444
July 2, 2014, 11:40 AM
I have what i believe is a Mauser 93 in .308. I have been reading online that they are pretty much not safe to shoot unless you have low psi ammo like 7.62. I bought it as a project gun and to make a shooter out of it, not knowing this beforehand. I only traded a beat up Type 53 and a cheap .22 scope for it so im not out too much if it is unshootable. What do you guys think?

tahunua001
July 2, 2014, 11:46 AM
not this again... just got done refuting this on another forum...
7.62x51 and 308 are nearly identical. one is measured in CUP and the other in PSI. the two really aren't comparable and if you actually measure both in PSI they have nearly identical pressures. slightly different case dimensions but one is not safer to shoot than the other. the only way to get "safe" ammo is load them yourself to a low velocity with a good medium burn rate powder.

in the end it's up to you whether you shoot it or not or risk the ammo you use in it.

James K
July 2, 2014, 12:17 PM
The "slightly different case dimensions" have not prevented thousands of rounds of 7.62 NATO from being fired in .308 Winchester rifles and vice versa with no problems. Those Spanish rifles, though, tend to be soft, so any extensive use should involve regular headspace checks.

But some of those have another problem; when the original barrel is rebored and re-rifled, the .308 reamer won't clean up a 7x57 chamber, so sometimes the conversion was done as shown in the picture. Is it safe? Probably. But I don't care much for the idea.

Jim

http://thefiringline.com/forums/attachment.php?attachmentid=41185&d=1232476324

Jim

barker2444
July 2, 2014, 12:24 PM
I probably will have it checked out by a gunsmith. All the horror stories about the soft metal fragging out into faces have me a little "Gun-Shy", pun intended. Thanks for your input! You can never be to careful.

emcon5
July 2, 2014, 12:53 PM
Having a gunsmith check it out won't make the metallurgy any better, or the action any stronger.

The action was built for the 7mm Mauser:

Maximum pressure (C.I.P.) 390.00 MPa (56,565 psi)
Maximum pressure (SAAMI) 351.63 MPa (51,000 psi)

For comparison, 308 Winchester:

Maximum pressure (C.I.P.) 60,191 psi (415.00 MPa)
Maximum pressure (SAAMI) 62,000 psi (430 MPa)

If you reload, the easy solution is to load down, using Hodgdon H4895 and their 60% rule.
https://www.hodgdon.com/PDF/H4895%20Reduced%20Rifle%20Loads.pdf

If you hunt, even downloaded it would make a nice handy little deer rifle.

barker2444
July 2, 2014, 12:59 PM
I do realize that.. i would just like to know if it is safe to shoot. Just because a gunsmith says it is doesnt mean it is but just to have somebody look at it and maybe do a barrel ultrasound would make me feel better. What do you recommend for load sizes or measurements? Im not a reloader but im sure my buddy can do it.

Hawg
July 2, 2014, 01:10 PM
I had a 1916 Spanish Mauser and fired several boxes of factory .308 through it but my gunsmith who also was a custom rifle builder and long range shooter told me if I kept doing it eventually the receiver would stretch until it was no longer operable. I will say it wasn't anywhere near accurate.

DPris
July 2, 2014, 02:37 PM
Barrel ultrasound?
Even if, that will tell you nothing about metallurgy in terms of receiver hardness.

Those conversions are shaky at best & not worth putting any serious money into.
Denis

Slamfire
July 2, 2014, 02:57 PM
This issue pops up all the time, such as in this thread where posters use current day pressure standards, make unsubstantiated claims for period proof test levels, and thus declare that a military FN Mauser is perfectly adequate for chambering in 338 Win Mag:

http://thefiringline.com/forums/showthread.php?t=545699&highlight=mauser&page=2

I disagree with assuming period pressures based on today’s standards. I have not found an explicit statement to the design loads that Paul Mauser used. SAAMI and CIP standards were established well after his death. However there is information about the proof pressures used in M98 actions.

Rifle Magazine Issue 159 May 1995 Dear Editor pg 10

http://www.riflemagazine.com/magazine/PDF/ri159partial.pdf

Ludwig Olsen :

Mauser 98 actions produced by Mauser and DWM were proofed with two loads that produced approximately 1000 atmosphere greater pressure than normal factory rounds. That procedure was in accordance with the 1891 German proof law. Proof pressure for the Mauser 98 in 7 X57 was 4,050 atmospheres (57, 591 psi). Pressure of the normal 7 X 57 factory load with 11.2 gram bullet was given in Mauser’s 1908 patent boot as 3,050 atmosphere, or 43, 371 pounds.

While many Mausers in the 1908 Brazilian category will likely endure pressures considerably in excess of the 4,050 atmospheres proof loads, there might be some setback of the receiver locking shoulder with such high pressures

Kunhausen shows similar numbers in his book : “The Mauser Bolt Actions, A Shop Manual”

Rifle & Carbine 98: M98 Firearms of the German Army from 1898 to 1918 Dieter Page 103.

M98 Mauser service rifles underwent a 2 round proof at 4,000 atm gas pressure, 1 atm = 14.6 psi, 4000 atm = 58, 784 psia.

The lugs broke on 1:1000 rifles used by the Bavarian Army Corp!

Unless someone can produce credible data as to the proof standards of later 98 actions, later K98 proof limits, and the design limits used by Paul Mauser, I am going to state that it is reasonable that the M91-M98 actions were designed to support cartridges of 43, 371 psia with a case head diameter of 0.470”. I have no reason to believe that later German/Spanish service rifle ammunition was of higher pressure as that would have had back compatibility issues with stores of obsolete rifles. While individual shooters may think it makes lots of sense to increase pressures to increase performance, for the military, logistical cost considerations will always outweigh the musing of dreamers.

I believe that a pressure standard for these rifles of 43, 371 lbs/ in ² is reasonable based on the SAAMI spec pressure of 35, 000 lbs/ in ² for the 8mm Mauwer. Obviously SAAMI researched this issue, probably determined original pressure standards, then used wise judgment about the age, uncertain previous history, unknown storage, usage, the known limited strength of period plain carbon steel actions, and as an industry, they were are not willing to accept the liability involved with selling new ammunition of a higher pressure.

As for CIP standards, I don’t know all that much about European proof testing, they do have a different culture and laws. Here, the proof test is conducted by the manufacturer, and if the gun breaks in service, the manufacturer is liable. A number of European countries have independent proof houses, the British I am a bit more familiar because I can read English. To sell your rifle in the UK you have to submit it to a proof house. Now the Proof House reputation is on the line, once they pass the thing, I assume they are liable. They also don’t care if your antique does not pass proof as long as they are paid for the test. If your blunderbuss fails proof, you can’t sell it. This would have the effect of reducing the number of old, structurally questionable rifles in use. Which then, are probably sold off to happy Americans!

The steels these rifles were built out of were plain carbon steels, which has been verified by a number of different sources:

Hatcher’s Notebook, page 230

German Mauser GEW 98

Analysis of the metal taken from several bolts and receivers indicates that they are made of plain carbon steel similar to SAE No. 1035, which has carbon .30% to 40% and manganese 0.60% to 0.90%.

A 1996 "core" assay of a generic WW-I era 1898 Mauser receiver:

http://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/4281076061?r=8481020161

I am unaware of anyone using plain carbon steels for firearms, well at least since the 60’s. FN might have continued using plain carbon steels in their commercial actions, don’t know. But Winchester, Remington, etc, all modern bolt rifles are made out of alloy steels such as 4140. This is a very common firearm steel. I have posted material data a number of times, don’t feel like trying to format it for this post. But, when ever I have read information on the quality of pre 1920 steels, it is all bad. You cannot assume the same steel made in 1890/1900/1920 will have the same material properties as the modern equivalent. Technology and process controls have improved considerably in the last 100 years. Just think, they did not have cell phones in 1900! In fact, many did not even have rotary phones. :( Without a phone, if you wanted to talk to someone, you had to be in the presence of the other person. :eek: Wow!, unthinkable cave man days! How did they survive back then? But, similar modern plain carbon steels show half the yield strength of alloys steels. This means if something goes wrong, the modern steel action is less likely to turn into a fragmentation grenade in your face. In the August 2014 Handloader Magazine, Mike Venturino shows a picture of a Swedish M96 based sniper rifle that blew its receiver ring. The statement is that a once fired 6.5 X 55 American made case failed at the case head. Interestingly, Venturino is also making the same wrong claims being made here, about old action strength by comparing modern day SAMMI and CIP standards. Those pressure standards were not in effect back in the 1890’s, nor up to WW1. Actually, I don’t know when they started. And, I would like someone to publish what standards were used, because this information is hard to find.

Spanish Mausers have a poor reputation for quality due to the number of posts of soft receivers. These are examples.

Quote:
http://www.jouster.com/forums/showth...1975#post41975
Soft rerceivers

I bought a 93 Spanish Mauser that had been rebarreled To .257 Roberts. The bolt had been ruined by Bubba trying to make it cock on opening. I bought it for a song and got a another bolt from Springfield Sporters and had a smith set the headspace and turn down the handle. Within only about 20 rounds of factory ammunition the brass started to show signs of excessive pressure... the bolt had already set back that much. I finally sold the gun less the receiver for about half what I had in it.

Not all of the 93's are like that and there is no way to know what Bubba had subjected that receiver to before he put on the .257 barrel.



http://www.thehighroad.org/showthread.php?t=530130
Quote:
Oceans - It is true, as I found out today, sadly.

I've had my 1916 Spanish Guardia Mauser from Samco for about 20 years now. Took it deer hunting every year until last year, when I heard about the same thing you did. I shot .308 rounds out of it.

Finally got the headspace checked by a gunsmith, and - well, the bolt locked EASILY on "no-go". And we're talking like butter. I snapped the firing pin and will have it hanging on the wall of my office soon

If you are shooting 308 ammunition in a Spanish Mauser you are shooting ammunition whose average pressure exceeds the proof pressures used when the rifle was new. There are risks doing that with old guns that have already been through one service life.

barker2444
July 2, 2014, 03:30 PM
So what im getting from this is i should just refinish it and get rid of it.

DPris
July 2, 2014, 03:41 PM
Passing it on to somebody else who may end up running into problems with it is between you & your own conscience.

But, you're right if you're getting the sense that it's not much of a shooter & not a "project gun".
Denis

barker2444
July 2, 2014, 04:38 PM
Well obviously i didnt know what i was getting myself into and maybe someone will buy it that does. I would never lie to someone or risk their safety for making money. There is no firearm worth a mans life. I dont know why you assumed that i would.

DPris
July 2, 2014, 05:07 PM
When you say "refinish and get rid of it", I may possibly be getting too cynical in my old age but it sounded (based on numerous similar comments over the years) like you were planning to make it pretty & pass it on to somebody else who probably wouldn't know what they were getting into, as you didn't when you bought it without research.

If you plan do sell it with full disclosure, you have my apology.
Denis

Slamfire
July 2, 2014, 06:36 PM
So what im getting from this is i should just refinish it and get rid of it.

Not necessarily. What I rant and rave against most is the misinformation and lies from authority figures that have become dogma in the shooting community. The most visible and active authority figures in the shooting community are gunwriters. For decades now, whenever a wave of old military surplus hits the shores, these guys get busy writing infomercials, “educating ” the American public with nonsense. Everyone has read about the “old world craftsmanship”, “German technology”, etc, meaningless un quantified terms . These guns are old guns, they were built to old standards out of old materials, and there are risks to the things, especially if you are shooting ammunition that exceeds the pressure levels these things were built to handle.

But,.. you can reload, you don't have to shoot 60,000 psia ammunition. Let me offer the suggestion of a 168 SMK 39.0 grs IMR 4895 LC cases, any primer. This is a very accurate load, see target below, when I have examined reloading manuals, this is around a 40,000 psia load. Assuming that your rifle is in good mechanical condition, no rust, no pits, headspace is OK, then this load is not higher than the service loads your rifle was built to handle.

If you experience hard bolt lift, sticky extraction, then your rifle receiver is junk and you ought to stop shooting the thing before something bad happens.

I shot this in a 100 yard reduced match, 20 shots for record, irons, prone with a sling. This is a good accurate load.

http://img.photobucket.com/albums/v479/SlamFire/Targets/M70Win200-14X168Nosler39.jpg (http://smg.photobucket.com/user/SlamFire/media/Targets/M70Win200-14X168Nosler39.jpg.html)

DPris
July 2, 2014, 07:52 PM
Loading down is always an option, if you or your buddy can keep you in reloads, and you're willing to accept lesser performance.
Denis

gyvel
July 2, 2014, 08:59 PM
I was always under the impression that Franco's rifles were converted to fire the 7.62mm round as it was loaded for the CETME, i.e. considerably less than standard NATO 7.62x51.

James K
July 2, 2014, 09:35 PM
Slamfire's post is excellent, but there is one area that is a bit misleading. Any rifle is proved with the proof load(s) of the caliber for which it is chambered. So a rifle, no matter what kind, chambered for 7x57 will be proved with the data for 7x57. If the same rifle, identical except for being chambered for 8x57 is proved, it will be proved with the appropriate load for 8x57. So proving a Model 1898 Mauser for 7x57 at 57k psi does not mean that an 1898 Mauser can handle only 57k psi; it means that 57k psi is the standard proof load for 7x57.

The maximum working pressure of the German 7.9 sS cartridge was 47kpsi, so presumably the proof pressure for a late Model 1898 would exceed that by the normal 30%, or 61k psi.

Jim

Mobuck
July 2, 2014, 10:08 PM
Many .308 starting loads are well within the capabilities of the 93/95 action. I've had 5 or 6 of the 1916 designation Mausers and fed them this type ammo w/o any problems at all. Makes them comfortable to shoot and suitable for plinking and short range hunting(similar to .300 Savage performance).

Slamfire
July 2, 2014, 10:48 PM
James: Thanks for the nice words.

The maximum working pressure of the German 7.9 sS cartridge was 47kpsi, so presumably the proof pressure for a late Model 1898 would exceed that by the normal 30%, or 61k psi

Your logic is correct, that is how proof pressures were normally calculated, 30 % above working pressure. But the data from Dieter’s book is verbatim 1905 reports from the Amberg Arsenal. The reports are about GEW 98’s in 8 X 57mm. I cannot explain the discrepancy. But that is the pressures they were using in proof testing Mauser 98 rifles that were then issued to German troops.

Rifle & Carbine 98: M98 Firearms of the German Army from 1898 to 1918 Dieter

Page 103.

M98 Mauser service rifles underwent a 2 round proof at 4,000 atm gas pressure, 1 atm = 14.6 psi, 4000 atm = 58, 784 psia.

Jim Watson
July 2, 2014, 11:26 PM
According to Lee Kennett (Gun Digest 1975), the 4000 atmosphere proof was standardized for the 1888 in 1893 and continued after 1911.
Cites here indicate it was applied to the 1898.

Under the 1911 smokeless rules, other rifles were to be proof tested with an appropriate powder to fill the cartridge within 4mm of the bullet base. Nothing said by Kennett about pressure.

The 1939 German proof law called for proof at 130% of service load pressure.

As said, the handloader has complete control over the round.
A starting load in .308 Winchester is very similar in pressure and velocity to a full power 7mm Mauser. This is no powderpuff, it will do anything to target or medium game you could ask for.

James K
July 4, 2014, 09:44 PM
Through the years, proof loads have been determined by various means, but usually are designed to be 25-30% over the standard operating pressure. That should be good enough; the goal is not to blow up brand new rifles, it is to ensure that they won't blow up with the standard load.

Springfield Armory not only proved the finished rifle, but also proved the barrels before assembly and even proved the barrel billet before it was machined. The purpose was to detect and weed out flaws at the earliest point, before time and money had been wasted completing a barrel and assembling a rifle only to have the barrel fail and destroy the receiver, stock and other expensive parts.

I had read that the same practice was followed by Mauser, but when I said that on a site devoted to Mausers, I was told that Mauser never proved any barrel until the barreled action had been fully finished and assembled. Maybe they proved at a lower pressure than Springfield did, or maybe they made better barrels or maybe they lost receivers, I don't know, but the Mauser experts assure me that no proving was ever done on barrels before assembly.

Jim