Pressure limits on the 1888 Commission Rifle is 36K CUP. Using modern or milsurp 8x57 in them is ...... foolish, at best ......... and hard on the gun (do you notice the headspace becoming excessive rather quickly?) ...... and eventually hard on the shooter, too.
Handloading, possibly with cast boolits, is pretty much the only safe/sane option for feeding these.
TheGolden Rule of Tool Use: "If you don't know what you are doing, DON'T."