Abstract: The present invention discloses a muzzle-loading firearm which includes a stock, a barrel integral with or fastened to the stock, having an opening of substantially constant cross-section extending longitudinally within the barrel from a muzzle end of the barrel toward the breech end of the barrel, and having a longitudinally extending chamber at the breech end of the barrel which has a larger cross-sectional area than that of the opening, a breech plug or other means for closing the chamber at the breech end thereof, and a lock operably connected to the chamber for igniting the charge in the chamber.