My .54 TC Renegade pet loads.
For patched RB. Mine likes 80 grains of 2f OR 3f, same volume amount of either one yields very nice groups. 75 grains is acceptable accuracy, but 70 grains is poor. I've never tried more than 80 grains of powder with PRB, no need with the groups 80 grains produces.
I get best groups with either .530 RB and .018" pillow ticking patches or .535" RB with .015" cotton patches.
Patch lube. I've tried all sorts of things. My absolute favorites are Track of the Wolf's mink oil, Frontier's anti-rust and patch lube, or a Dutch Schultz style "dry lube of 1 part Castor oil to 6 parts water. The mink oil is very slick and best groups are with a very light coating of it, just barely enough to coat the patches to the edge (I apply by hand by putting some in the center of the patch and then rubbing it out to the edges with my thumbs). I swab the bore between shots, night and day difference in ease of loading with the light amount of patch lube I use.
I've only tried one kind of conical, a Hornady 425 grain Great Plains Bullet (no longer made). It shot that best with 100 grains of 2f.