RE: .50 or .54??
I have a 54 in a flint and a percussion in the Deerstalker I get excellent groups with both guns. I shoot 50 cal bullets in a sabot and 444 gr powerbelts. I get good results with a .530 PRB with a .10 ticking patch I use between 80 and 90 gr of 2 f goex in the flint and Goex Pinicale in the percussion.