I too enjoy using fffg black powder in 45 colt. Man,,,what a boom.
It's enlightening. It's part of why we chose the 45 colt. Think about it: You could have chosen a 44 magnum and it might have served you better. But no, the 45 has this sort of hallowed mystique from the Old West about it that the 44 magnum doesn't. Load it with a full compressed charge of fffG black-powder; the results will be impressive! It will drive a 255 grain lead bullet close to 1,000 fps.