I built myself up a sporting rifle around an original '59/'63 Sharps lock plate.
These percussion to center fire conversions were chambered in the 44/77 Sharps Sporting Rifle or 50/70 Gov.
However, at the time of the build the 44/77 was either not available or in the case of the 50/70 brass was too expensive at $2.50 (+) each. I chose to chamber it in 45/70.
My 405 Lyman bullets, in pure lead, cast in at 420 grs. This worked out fine at the 600 meter range I had access too.
With BP and a rot at 1-16 and a 30" barrel the 420 gr. bullets worked fine if I did my job with the sight corrections. I did not like the felt recoil of a full match in the 45/70 at what would be thought of as mid range for this cartridge.
My best,
Blair