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.
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.