My own starting load for a .45 caliber of different style but similar bore was a .440" ball, pillow ticking patch, wet with saliva and cut at the muzzle over 15 grains of Goex 3f. I chronograped the load at over 900 fps and the first five shots fired went in a group just over 2" at 25 yards. I know 15 grains doesn't sound like much but 900 fps sure seems like plenty. I was shocked at the speed because I've mostly played with revolvers in the past and I know 15 grains won't do much over 700 fps from my .44 revolvers and 900 fps is about all you can get from a revolver with black powder. Certainly the pistol can be loaded much heavier but why bother?