BONANZA, you can use the load data for the 8X57 Mauser, less 5% and work up from there! The 8x57 Mauser works in the range of around 46,000 PSI, and the 8x57JR at about 44,000 psi, both useing a 196 gr bullet! That is, if your rifle is in good condition! Don't sweat the small stuff, the 8x57JR is a very good cartridge, and is a fine rifle for anything up to, and including Moose!