A firearm system includes a bolt carrier with an internal cavity, a piston disposed within the internal cavity, a forward configuration where the piston is in a forwardmost position relative to the bolt carrier, and an aft configuration where the piston is in a rearmost position relative to the bolt carrier. The piston slides forward and aft relative to the bolt carrier. In the forward configuration, the entire piston remains disposed within the bolt carrier.

One embodiment of the present invention provides a polymeric ammunition having a metal injection molded primer insert.

One embodiment of the present invention provides a polymeric ammunition having a metal injection molded primer insert.

The rifle system comprises a rifle and an ammunition round for operation with the rifle. The high pressure ammunition round further comprises a cartridge case having an outer wall wherein prior to firing of the ammunition round, the outer wall geometry of the cartridge case is devoid of features configured for interfacing with a mechanical extractor. The rifle further comprising a barrel chamber which fully supports a chambered cartridge case and a rear extraction mechanism for extracting a spent cartridge case through the rear of the barrel chamber.

One embodiment of the present invention provides a polymeric ammunition having a metal injection molded primer insert.

One embodiment of the present invention provides a polymeric ammunition having a metal injection molded primer insert.

One embodiment of the present invention provides a polymeric ammunition cartridge and methods of making and using the same. The cartridge includes a substantially cylindrical insert connected to a substantially cylindrical polymeric middle body. The substantially cylindrical insert includes a top surface opposite a bottom surface and a substantially cylindrical coupling element that extends from the bottom surface, a primer recess in the top surface that extends toward the bottom surface, and a flange that extends circumferentially about an outer edge of the top surface. The substantially cylindrical polymeric middle body includes a substantially cylindrical polymeric bullet-end and a substantially cylindrical polymeric coupling end connected by a powder chamber, wherein the substantially cylindrical polymeric coupling end contacts the substantially cylindrical coupling element.

One embodiment of the present invention provides a polymeric ammunition cartridge and methods of making and using the same. The cartridge includes a substantially cylindrical insert connected to a substantially cylindrical polymeric middle body. The substantially cylindrical insert includes a top surface opposite a bottom surface and a substantially cylindrical coupling element that extends from the bottom surface, a primer recess in the top surface that extends toward the bottom surface, and a flange that extends circumferentially about an outer edge of the top surface. The substantially cylindrical polymeric middle body includes a substantially cylindrical polymeric bullet-end and a substantially cylindrical polymeric coupling end connected by a powder chamber, wherein the substantially cylindrical polymeric coupling end contacts the substantially cylindrical coupling element.

The present invention provides a primer insert for use in a polymeric ammunition cartridge includes a top surface opposite a bottom surface and a extraction flange that extends circumferentially about an outer edge of the top surface; a coupling element that extends from the bottom surface, wherein the substantially cylindrical coupling element is adapted to receive a polymer overmolding; a primer recess in the top surface that extends toward the bottom surface, wherein the primer recess comprises a recess bottom and a circular recess side wall; a primer flash aperture through the recess bottom that extends through the bottom surface, wherein the primer flash aperture is adapted to receive a polymer overmolding to form a flash hole; and a groove in the primer recess positioned around the primer flash aperture adapted to receive a polymer overmolding, wherein the groove extends at least partially over the bottom surface and at least partially over the circular recess side wall and the groove is adapted to receive polymer over the bottom surface and at least partially over the circular recess side wall.

The present invention provides a primer insert for use in a polymeric ammunition cartridge includes a top surface opposite a bottom surface and a extraction flange that extends circumferentially about an outer edge of the top surface; a coupling element that extends from the bottom surface, wherein the substantially cylindrical coupling element is adapted to receive a polymer overmolding; a primer recess in the top surface that extends toward the bottom surface, wherein the primer recess comprises a recess bottom and a circular recess side wall; a primer flash aperture through the recess bottom that extends through the bottom surface, wherein the primer flash aperture is adapted to receive a polymer overmolding to form a flash hole; and a groove in the primer recess positioned around the primer flash aperture adapted to receive a polymer overmolding, wherein the groove extends at least partially over the bottom surface and at least partially over the circular recess side wall and the groove is adapted to receive polymer over the bottom surface and at least partially over the circular recess side wall.