I have to agree with what JB says based on my experience with three rifles chambered to the 7x57. My M70 Featherweight will run 2800 FPS using Re17 and the 150 gr. Nosler Partition as will my Ruger #1A. They will also run 2800 FPS running a load of W760 and the 140 gr. Nosler Ballistic tips. However, my custom Mauser 7x57 balks at just about everything I've run through it. Camber dimensions are a bit tighter than the commercial rifle but the neck section of the chamber is open enough that it's not the problem. The throat is long enough that 170 gr. Sierras can be seated far out enough yet still not contact the rifling. I loaded some to duplicate as close as possible to the original 1892/3 specs and ran them over the chronograph. The Winchester and Ruger were right on the money will only about 20 FPS difference. That same load was 150 FPS faster than the two commercial rifles running the exact same load. I have yet to figure out what the hell is going on with that rifle.
Paul B.

Our forefathers did not politely protest the British.They did not vote them out of office, nor did they impeach the king,march on the capitol or ask permission for their rights. ----------------They just shot them.
MOLON LABE