I Just happen to catch this thread I think I may have info for you as Ive owned a Traditions BH Pro for several years.
#1 Tune the trigger, shorten sear engagement and polish contact points.
#2 Tripple 777 powder shoots well in my gun not pyrodex 70-80gr. w/260&320gr. Lee R.e.a.l. bullets
My pistol misfired 50% with percussion caps even after I beefed up spring so I went to Musket cap nipple and got 100% ign. I also changed sights to T/C contender sights.
I have shot 395gr lyman great plains bullet w/80 gr. of T777 and hold onto your hat buckwheat cause the earth is gunna shake... most factory bullets didnt do too well however lees and lyman did. Sabots are very hard too stuff down a fouled barrel but Ive always wanted too try a power belt because Ive heard lots of good things about them. I realy like my BH Pro 50 cal but tuning is a must as factory ready to hunt is a myth beyond 35 yds. try alot of differant bullets and powders off a bench and make sure you use good quality caps, seat bullet against powder with 1 firm push but dont tamp. Try 65, 70, 75, &80 grains powder with same bullet then again w/ next style bullet and next. My best group was 1 1/2" at 25yds w/260gr lee real & 70gr of T777 and 1275 fps. I am confident to 100 yds but gun hasnt been used on game yet but its matching nickel rifle has. Have fun.
Patrick