I did get out between rainstorms and tested the 71 Mauser.
It shoots about 18 inches high at 100m with the lowest sight leaf, which i understand is typical of these rifles which were zeroed at 300m. Since the rear sight notch was small, I think a man-sized target past 300m would be challengeing. The sights are graduated to 2000m for 'volley-fire' only, I'm sure.
Anyway, the fired cases showed some interesting details. First, the shoulder was blown foward compared to the cases made from 348 brass by Buffalo Arms. No cracks nor splits, just some unexpected fireforming.
The casemouth of fired cases measured: ID: .448 and OD: .470.
So, given those measurements, and having .433 lands and .451 grooves; should I go with:
1. .443 bullet, .005 (man, that is THIN) paper patch; and use real Blackpowder to obturate to groove size?
lets say i dont want to use real black. are these viable options?
2. .448 total diameter patched bullet, some hornet nesting (*) to prevent gas blowby, and 30-35gr IMR-4198? Hogdon 4198? Triple7?
3. try to load a .451 bullet, swageing it down to fit in the casemouth; and hope it chambers (or shove really hard- j/k)
(*) is there an alternative to hornet nest material for preventing 'blown' patches (admittedly a trick from the patched ball shooters)? also, does 777/Pyrodex cause the same obturation as real blackpowder?
Thanks all for your expertise!