Patent attributes
A firearm ammunition cartridge comprises a case having a substantially tubular body portion, an open leading end, and a trailing end defining a primer port. An insert is received within the case and extending along the body portion. The insert has an exterior surface conforming to an interior surface of the body portion and a central cavity extending along an axial dimension of the insert. The central cavity opens to the primer port at the trailing end of the case and to a leading end of the insert. A quantity of gunpowder is disposed within the central cavity, and a projectile is received and retained within the leading end of the case. The gunpowder is confined to a chamber comprising at least a portion of the central cavity between said case trailing end and the projectile.