I just wanted a slower moving 6mm. Two of the Spaniards I have have already been converted to the 7.62 NATO (7.62×51mm CETME) so feeding should be no problem because the rails would alredy been modified.
If a Spanish 308 Win conversion blows, who you going to sue? The Spanish Nation? Just because the Spanish military or some other military converts their 7mm Mauser actions to 308 Winchester does not mean it is safe. What it means, is that the Spanish military has a callous attitude towards the lives and health of its Soldiers, Sailors, Airmen, and Marines. It was not that long ago that the US military issued low number M1903 Springfield rifles, about 1,000,000 to its troops. This was after tests that showed about 33% percent of these rifles would come unglued in overpressure incidents. Officially the statement was that the rifles would be left in service until worn out and then the receiver would be scrapped at Depot. What the press release ignored was the fact that a certain number of these rifles would blow up, injuring its user, before it was returned to Depot. The Hierarchy of the US Army, Navy, Marine Corp made this decision knowing full well the consequences to its service men. Leadership considered the life and health of a service man to be worth less than a $40.00 rifle. What makes anyone think the Spanish military were any more enlightened? The aristocracy of all nations consider their subjects as disposable for their greater good. Spending money protecting the great unwashed is not part of their greater good.
The pressure data for the M98 also applies, as far as we know, to the small ring Mausers:
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
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. Page 103. A comment on the metallurgy and process technology of the era, Dieter found records that indicated that the bolt lugs broke on 1:1000 of GEW98 service rifles used by the Bavarian Army Corp!
Gun Digest 1975 has an excellent article,
“A History of Proof Marks, Gun Proof in German” by Lee Kennett.
“The problem of smokeless proof was posed in a dramatic way by the Model 1888 and it commercial derivates. In this particular case a solution was sought in the decree of 23 July 1893. This provided that such rifles be proved with a government smokeless powder known as the “4,000 atmosphere powder”, proof pressure was 4,000 metric atmospheres or 58,000 psia. The 4000 atmosphere proof was standardized for the 1893 and continued after 1911.
The article indicates it was applied to the 1898. The 1939 German proof law called for proof at 130% of service load pressure. From
Mauser Bolt Rifles by Ludwig Olsen, page 134, The maximum working pressure of the German 7.9 sS cartridge was 46, 926 psi. According to sources, this round was used in machine guns after WW1 and then shortly before WW2, became a universal issue round. Use in the K98 action had to have been examined, and I expect the decision to use in the K98 would have been based on the improvement of metal quality and process technology. A proof pressure 7.9sS would be 61k psi.
So, cartridges operating at 60,000 psia are operating at the proof pressures of these old military actions. Unless someone can produce credible data as to the proof standards of later 98 actions, and the design limits used by Paul Mauser, I am going to state that it is reasonable that the small ring mausers and the M98 action was designed to support cartridges of 43, 371 psia with a case head diameter of 0.470”. Later higher pressure ammunition was probably considered an acceptable risk, but even then, the 7.9 sS World War 2 cartridge pressure was 46,926 psi.
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. 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.
I have converted many a Mauser to different taper cases with no problems. This one I am not worried at all. Besides the lower steel is not Spanish but from a 6.5 Swede.
When you experiment with cheap old military actions, operating them constantly at pressures above their service pressures or their intended pressures, you invite some particular and predictable risks. If the receiver seats are peened, due to high pressures, case head protrusion increases and it is only a matter of time till the case sidewalls blow. If the bolt lugs crack, through fatigue fracture, with these small ring Mausers, the bolt can be blown out. From web postings on another forum, this has accounted for at least two fatalities. I think one was a shooter in Australia and one was a Swedish Service man. After the death of the service man, Sweden dumped all their old M1896 rifles on the American market. You can, if you want, study the pressure the Swedes used, and their old plain carbon steel actions were not operating at 60,000 psia. Swedish steel may (and this is an assumption) may have been better than Spanish, but actions made prior to 1920 were pre vacuum tube technology. Spain had a Civil War in the 1930’s, so it is likely the rifle factories were not being technologically upgraded as people were cheap.
These old actions are cheap, and that is for a reason, they are cheap. They are metallurgically weaker than the same receiver made of modern alloy steels. The fatigue life is less, in fact, quite unpredictable.
If you are building these actions for others, understand your liability. As a gun manufacturer you are assumed to know more than your customer. You are assumed to be an expert. If one of your conversions blows up in the hands of another, and you converted it to an inappropriate cartridge, in a product liability lawsuit, you will lose everything you own, and everything you will ever own.
However, if you are making these for yourself: Go have at it. You are responsible for you own life and limb and if you don’t have the knowledge, and don’t heed the warnings, well, it is on your head and no one else.
