Patent ID: 7743705

Claim:
A projectile for use in a barrel with a plurality of stacked projectiles, including: a chamber containing a propellant charge for the projectile, an exit from the chamber for release of propulsion gases into the barrel when the propellant is ignited to fire the projectile, the exit including a sealing surface, a seal blocking the exit by sealing against the sealing surface of the chamber, wherein the seal is opened by ignition of the propellant within the chamber but is resistant to propulsion gases from other projectiles in the barrel and is forced further into engagement with the sealing surface by pressure from propulsion gases from other projectiles in the barrel, and a retainer engaging the seal into engagement with the sealing surface, wherein the seal is deformable between a closed condition and an open condition by deformation, and wherein the retainer includes a supporting stop for confining the deformation of the seal.