Be aware that some of the substitutes are formulated for inline actions using 209 (shotgun) primers, and won't ignite reliably in a percussion or flintlock firearm. Best bet is to stick with real BP, although I have had excellent results with APP (American Pioneer Powder/ Shockey's Gold) in a .54 cal Lyman Great Plains caplock and a Remington cap & ball pistol. It is a little less energetic than real BP or some of the subs, but it is a pleasure to shoot since it is less corrosive than most and creates some moisture as it burns, which keeps fouling soft and makes long strings possible (as well as making cleanup easier).
