I would have thought that a strong modern action like a ruger 77 hawkeye which easily withstands magnum cartridges like 300wm, 7mm mag, and 375 ruger wouldn't have much trouble safely eating 7x57s loaded to a more modern velocity.
Objectively, it seems that the greater case capacity of the 7x57 should allow it to exceed 7mm-08 velocities at any bullet weight (7mm-08 Remington (R-P): 52.2, grains7x57 Mauser (W-W): 55.6 grains :taken from chuckhawks).
The SAAMI pressure of 51,000 PSI for the 7x57 vs the 61,000 PSI for 7mm-08 seems excessively conservative for modern rifles. I've heard (anecdotally) of guys loading 7x57 to 7mm mag velocities without rifles blowing apart (not that it's a good idea anyway).
I'm not arguing that powder, bullet, and cartridge manufacturers aren't publishing data that says the 7mm-08 loads are always faster. It's just that something seems fishy about a cartridge with a greater capacity not being able to even match another with the same bullets.
I also question the safety concerns over marginally over-pressure loads in strong modern actions. I remember a guy testing a Swedish Mauser (a design considered weaker than the M98) by progressively increasing charges until the rifle failed. If I recall correctly, it took an extremely over loaded cartridge (much more than any handloader would reasonably develop) to actually damage the receiver to the point it could not longer be used, and even then it didn't explode and a potential user would probably not have been injured. And this was with an action considered inferior to the M98.
I am by no means an expert. I'm just curious if there is a rational explanation for the 7mm-08 being faster than the 7x57 in spite of a lower case capacity. Otherwise I'd assume it was just a liability thing related to weak M93s.
