After putting a black powder .45-70 RNL bullet straight through a buffalo at about 80 yards from a Pedersoli Sharps replica, I no longer think that there's any point to the -90 and bigger versions. AFAIK you lose accuracy and gain, well, nothing. In a Sharps, a 525-grain bullet fits fine, and it really is all you'll ever need. You can't tell the exit hole from the entrance hole, on a buffalo. You really don't need more power than that.
.45-70 and .50-90 are well-balanced cartridges. There's really no point in getting the oddball .45-120, which was a failure in its own time since it didn't work.
.45-70 and .50-90 are well-balanced cartridges. There's really no point in getting the oddball .45-120, which was a failure in its own time since it didn't work.