Back in the days when we were allowed these guns in the UK I had a .44" Bulldog and loaded it with Black Powder under a .429" bullet, God knows what it weighed but it was cast from the Factory Mould for the Colt Army, repro of course.
It shot, that's all I am prepared to say! Cleaning was a nightmare, smoke was great! I loaded cut down 44 Special Cases and had about 10 spare. It was an experiment, nothing else and not one that I have ever done since. In fact the gun was cashed in during the Pistol ban, I seem to recall it made £150 which was nearly ten times what it cost!