I'll try. I'll use the 7x57 as my main example. Because there are so many weak(?) 1893 and 1895 Mausers chambered to the 7x57, SAAMI pressure has been limited to 45,000 C.U.P./50,000 P.S.I. Factory ammo and most load data is kept to those pressure levels. But what is the true pressure level for that cartridge? Take a Winchester M70 or Remington M700 rated as high as 65,000 P.S.I and shoot a 7x57 cartridge loaded to that pressure level. That's the true potential of that cartridge. Not 45,000 C.U.P/50,000 P.S.I.
It's kind of like putting a 2 barrel carb on a 460 Cobra.
Yes, and you can understand why if you think of liability laws and gunwriters. Gunwriters are pitchmen for the industry and every time a new batch of antique Mausers come in, they print copy extolling the virtues of the things. Terms like “Old World Craftsmanship”, and “German” or “Swedish” steels pop up in the articles, basically meaningless, but effective in creating the impression that these old rifles are somehow super strong. They aren’t. Those WW1 era and earlier rifles are made of low grade steels that were full of slag and inclusions. Additionally they were not designed or built for high pressure rounds.
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 10http://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.
Incidentally, the lugs broke on 1:1000 rifles used by the Bavarian Army Corp!
Given that the general public is under the impression that these old antiques are “uber” strong, they will not be in the forgiving mood if one blows up with factory ammunition. Ammunition companies will be under great potential financial liability if their ammunition is in one of these blowups, so they must download these historical cartridges to the lowest common denominator.
However, if you have a modern action, (post WW2) made of modern materials and are using modern cases, and know what you are doing, I don’t see any reason why you can’t develop higher performance loads in the 7mm Mauser. You will be doing it by your seat of the pants since you don’t have pressure gages, but, as long as you don’t have sticky extraction, blown primers, expanded case heads, and your velocities are reasonable when compared to cartridges like the 7mm-08, (not the 7mm Rem Mag!) you should be perfectly fine.
Well there's nothing new under the sun, I guess. I wonder how the superformance ones would do if Hornady knew they could guarantee that they'd be shot in turnbolts only (which they can't, but.....). Probably a lot better though - i.e. real benefit from technology would be my guess, with same pressure.