This past week I shot my 93 turkish mauser sporter and compared the current 8mm mauser offering from winchester to a much older winchester "super speed" offering I purchased off of gunbroker. The current production is a 170 grain power pointed loaded to a light 2300 or so fps. I am told this light loading is due to concerns over use in old tighter bore rifles that had a bore of 0.318. The older super speed ammo used a 170 grain bullet as well but is a round nose projectile.
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 WW1 and earlier Mauser 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!
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. 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.
Unless someone can produce credible data as to the proof the design limits used by Paul Mauser, I am going to state that it is reasonable that early Mauser actions were designed to support cartridges of 43, 371 psia with a case head diameter of 0.470”. 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.
It is prudent to keep pressures low on rifles built before the 1930's, especially on rifles from WW1 or earlier. Early Mauser models, such as your M93, do not have the shooter protection features that the great M98 has built into it. At pressures less than catastrophic metal failure, the M98 will vent gases away from the shooter. Those earlier actions: gases go right in your eye. None of those pre 1920 actions are actually any stronger than any other, as they were all built out of the same plain carbon steels. Steels which, are so low grade and cheap that today they are used for rebar and rail road ties. The M98 might handle a bit more pressure as the inner collar provides strength and safety that the earlier models lack, but still, overall, they are all in the same strength class due to the inferior metals and inferior process controls of the period.
Your M93 Turkish rifle, I have no idea when it was built, and you have no idea of how many service lives it has gone through. Modern actions, made of modern alloy steels, they can take a lot more pressure and firing cycles, and that, in my opinion, is why commercial ammunition is loaded rather light for older cartridges.
Before someone chips in about Norma ammunition, which is much hotter than commercial US, people ought to look at the proof laws in Europe. European have a different culture than the US. One visible aspect is firearms proof laws. Americans all act and think as if they are firearms experts. When it comes to firearms, Americans are Confident Idiots.
http://www.psmag.com/health-and-behavior/confident-idiots-92793 The European system assumes gun owners are not experts. I bought the book " Standard Directory of Proof Marks " for the proof marks, and it was not until 20 years later that I read the text. The best section was on German proof marks. I found that many countries that have reciprocal, "equivalent" proof laws with Germany. Under the German system, you cannot buy, sell, or trade a firearm without the firearm going to the proof house. If the firearm fails proof inspection, for whatever reason, the offending part is destroyed. Prior t o the 1960s the whole firearm was destroyed. I am certain owners of expensive scope mounts, scopes, stocks, barrels, were greatly upset when all of the parts and pieces of their rifle came back in shards, and only the bolt stop was actually defective! . I am certain after the 60's law, requiring only defective parts to be destroyed, a lot of proof house workers thought the fun had gone out of the business. But the intent and effect of European proof laws is to remove old firearms from the shooting community. No one in their right mind is going to sink $1000's of EU's into some old action, even if it only has a medium risk of failing proof. The proof house does not care about your feelings or cash layout, they exist as gate keepers, keeping unsafe and inferior firearms out of the populace. And the workers probably have fun smashing your firearm into bits. So, Norma can sell much hotter ammunition in Europe as the old clunkers have been taken off the road by proof laws.
As to your rifle shooting higher or lower with different ammunition, well, that is what elevation knobs are for. Trying to figure it out will only result in frustration as the dynamics of the system are complex, and probably chaotic.
