Patent ID: 7621064

Claim:
A muzzle loading firearm comprising: a barrel having a bore defining a bore axis, and having a muzzle end and a breech end; a breech plug having a nose, a substantially planar rear face opposite the nose, a primer pocket formed in the rear face to receive a primer flush with the rear face, the primer pocket having a peripheral inner surface adapted to be substantially contiguous to an outer surface of said primer, a passage extending through the breech plug from the primer pocket to the nose, and an outer surface having interrupted threads formed thereon, the interrupted threads extending from the nose toward the rear face along a portion of the outer surface and being configured to engage corresponding threads formed in said barrel bore proximate said barrel bore breech end, the outer surface further comprising a second portion distal from the nose and adjoining the rear face, the outer surface second portion being configured to receive torque to cause the breech plug to rotate around said bore axis; a breech element pivotally connected to the barrel, and having a breech face, the breech element being movable between an open position in which the breech face is away from said barrel breech end, and a closed position in which the breech face is in substantially planar contact with said rear face of said breech plug; and a firing pin carried by the breech element such that when the breech element is in the closed position, the firing pin is aligned with the primer pocket.