I have two .54's both with Montana barrels. For range work I use a .535 ball, .022 denim patching over any where from 60 to 90 grains of 2f Goex. Hunting I use 115 grains of 2f Goex, same patching and ball for the load in the barrel, .530's in the loading block.
Barrels are .540 bores with about .015 deep grooves, 1 flint, the other cap.
I never drank the Pyrodex, T7, whatever Koolaide.
Hope this helps.