IHAVEUSED EVERY THING FROM A 40 TO A 62CAL ANDI ENDED UP USING A 54 FOR EVERYTHING BUT TARGET AT SHORT RANGE WHICH I USE A 45 FOR. I have take boar deerelk and a bear that weighed in at 680 field dressed with one shot and round ball with a 54cal, my best one is a copy[ I bought the plans from a musiem in St Louis ,MO]I made my self with a 35.5 inch barrel, it shoots best with 535 PRB and 130 gr of RS; I have shoot 19 inch strings at Friendship with it and taken deer and bear at 175 yds. It has a 1-80 twist.
Due to the fact they do not make a barrel that has the right twist to shoot a heavy load a 58 will never be any good for long range and even if they did the recoil that would be developed if you pushed a 360 gr ball to 2000 fps would be noticable. Lee