i use 45-90 cases with rims turned down about 10 thou and sized, with standard large pistol primers, 300 grain .452 cast bullets sized down to .446", and 14 grains blue dot for about 1000 fps plinking. 45/70 cases are cheaper, but come up short. the thin rim of the "non-mauser" case allows primer to back out about 1/16". original 11mm mauser cases had a thicker rim than any comparable american cartridge. NBD in low power loads.
factory loads were a 370 at 1450. 4198 powder is the best choice. it was designed as a "40% substitute" for black powder. use charge weights 40% of what the black powder weight was for same ballistics in BPCR. of course, the 71 and 71/84 mauser lock up on bolt root only, so everything is "your own risk".
the 71 was widely used in african colony secondary status till ww2. the 71/84 (tube repeater) was only issued 4 years, replaced in 1888 by the "commission rifle", so was surped into USA via outfits like Bannermans, that cut many 32" bbld rifles down to about 24", like the carbine version I have. the 71/84 was actually issued to reservists in ww1, so was surped in 1920 or so. val forget brought several thousand in that were "reconditioned" to look like japanese murata 11mm rifles for teh tom cruise movie, "the last samurai". you see these from time to time with softwood stock refits and bluing over pitting.
numrich has some small parts, including the bolt stop. this part often breaks. be advised that the magazine cutoff must be set to single shot mode, keeping the cartridge lifter up, before the bolt can be removed. tricky gun to disassemble if you don't know it's quirks. disappointing to think of this even as a first try for paul mauser, but a fun shooter and the first bolt action repeater ever issued for military service.
