That is real good shooting for open sights at 50 yards. A lot of the scouts were a 1:38 twist which made them good conical shooters. I think a few were also 1:48 twist.

Some other bullets to try would be a maxi ball. That load would sure do anything moose size and under in. As mentioned, you might want to lower the charge and see how that shoots, but if it likes that much powder, and you like the recoil. Go for it.