There are 8x57s and then there are 8.57s. The first commission rifles, the M88s, were chambered for the 8x57J which used a round nose .318" diameter bullet. With the mauser 98, they redesigned the 8x57 with a .323" diameter "8x57S (for Spitzer)" bullet. Obviously, trying to force the 8x57 .323" S bullet down a .318 bore is NOT good and to add to that the S shoots higher pressures due to the fact that the 88 commission rifle really wasn't as strong as the 98, then you have Turkish 8x57S out there that is really high pressure, well, you have to watch out and know what you are doing, slug the barrel, know the caliber, before you go firing that old Mauser if it isn't a 98. I have an 88 commission rifle that was rebarreled to 8x57S for use by second tier troops, hitler youth, and that. I've fired Turkish ammo out of it without problems. But, I don't shoot it often anymore. I picked it up in the 70s for $27.50 in NRA very good. How could you turn that down? LOL It has one of the smoothest bolt throws on any rifle I've ever picked up, superb attention to fit and finish, even if it's not as strong as a 98. It is a testament to how they built 'em back then.
To add to that confusion, there were rimmed versions of both J and S rounds for use in German sporting arms, the break open drillings which has a rifle barrel under two shotgun barrels. There was a rimmed J called the 8x57JR and a rimmed S called, I think, the 8x57RS or SR or something. My uncle brought a JP Sauer drilling back from Germany in 8x57JR and I've fired it. It was a neat gun, but used the oddball .318" bullet.
