When trying to load for a Model 71 Mauser, given that the bore slugged out to be .433 lands and .451 grooves, what size bullet shoudl i use?
The loaded ammo available from Buffalo Arms and grafs have .443 bullets, not paper patched. Loose .443 projectiles are available. So are .451-.452 diameter bullets.
I figure .433 bullets are too small to seal the bore, even with patching.
But, for safety and hopefully accuracy, would you go with .451's unpatched, or .443's patched with some paper that is 0.04-0.045 inches thick patched around it?
For informational purposes, the 71 Mauser original load was for a 380-ish grain paper-patched lead bullet in front of 77gr of black powder, pushing ~1450 fps. I understand BP helps seal the bore by obturating the bullet.
My choices of powder can be either 77gr BP Equivalent of Pyrodex RS, or Triple SeVen or ~30grains of H-4198.
Any help appreciated!