Gote, most pistols are set up with a slower twist and tend to shoot round balls better. I've tinkered with short conicals in them, but the round balls were more accurate. I don't have the Kentucky, but I shoot a Traditions Trapper often. It prefers 35 grains of 3f and a wad between the powder and ball. Your most accurate load in a .50 will probably fall within the 25-35 grain range.
Max load should be around 50 grains or so. If I remember right, Traditions says the max load for my Trapper should be 45 grains, but you know how conservative the makers ratings are.
If you try a conical, keep it as short as possible. The Buffalo Ball-et was designed to be shot in slower twist guns, so it might work well for hunting. I have shot them in my Trapper with decent results. Not as accurate as a round ball, but plenty accurate enough for hunting. Good luck to ya!
