There are certainly no flies gathered on the original chambering of 8x57JS.
Properly loaded, it is a potent, dynamic package.
I have a 700 "Classic" so chambered, and it is a very effective unit, with 2 Moose and 2 Black bears to it's credit. [1 shot each, BTW.]
The 180 can be driven to 2800+, and the 195-200's to 2650+. Mighty good medicine, that!!
Norma and RWS, as well as PRVI all load this cartridge closer to its potential.
Our North American loadings resemble 300 Savage, not near the potential of the 8x57JS. [plus mostly in the 170 grain flavor]
I would keep it as is, shoot it and see. You may already have a winner in that Mauser!
Cheers, Eagleye.