Hello C.Davidson,

Agree with HeymSR20!
I use the 7x57 since 1972. In all the modern rifles chambered for it, you can load it up significantly. As a starting point, you can use with total confidence the loads for the 7-08 Remington.
As Heym say, in my M98 Mauser 7x57 I reach 2650 f/s with the same H-Mantle 173 grs, and with any 175 grs bullet as well.
As an all around bullet weight, 154 to 160 grs is a very good choice. Changing the bullet type, not weight, as a function of the game.

Good luck!

PH