The present invention provides a subsonic ammunition cartridge including a polymeric casing body comprising a generally cylindrical hollow polymer body having a body base at a first end thereof and a mouth at a second end to define a propellant chamber; a propellant insert positioned in the propellant chamber to reduce the internal volume of the propellant chamber, wherein the propellant chamber has an internal volume that is between 25 and 80% less than the open internal volume of a standard casing of equivalent caliber; and a primer insert positioned at the body base and in communication with the propellant chamber.

The present invention provides a method of making a two piece primer insert comprising: an upper primer insert portion comprising an upper primer bottom surface, an upper primer aperture through the upper primer bottom surface; a substantially cylindrical coupling element extending away from the upper primer bottom surface, and an interior surface; a lower primer insert portion comprising a lower primer bottom surface opposite a lower primer top surface having a primer recess, a lower primer aperture through the lower primer bottom surface, and a flange adapted to receive a polymer overmolding that extends circumferentially about an outer edge of the lower primer top surface; and an insert joint that links and aligns the upper primer bottom surface and the lower primer bottom surface to form a primer insert.

The present invention provides a method of making a two piece primer insert comprising: an upper primer insert portion comprising an upper primer bottom surface, an upper primer aperture through the upper primer bottom surface; a substantially cylindrical coupling element extending away from the upper primer bottom surface, and an interior surface; a lower primer insert portion comprising a lower primer bottom surface opposite a lower primer top surface having a primer recess, a lower primer aperture through the lower primer bottom surface, and a flange adapted to receive a polymer overmolding that extends circumferentially about an outer edge of the lower primer top surface; and an insert joint that links and aligns the upper primer bottom surface and the lower primer bottom surface to form a primer insert.

The present invention provides a multi piece primer insert for ammunition comprising: an upper primer insert portion comprising an upper primer aperture through an upper primer bottom surface; a substantially cylindrical coupling element extending away from the upper primer bottom surface, and an interior surface; a lower primer insert portion comprising a lower primer bottom surface opposite a lower primer top surface, a primer recess in the lower primer top surface adapted to fit a primer, a lower primer aperture through the lower primer bottom surface, and a flange that adapted to receive a polymer overmolding extends circumferentially about an outer edge of the lower primer top surface; and an insert joint that links the upper primer bottom surface and the lower primer bottom surface to form a primer insert.

The present invention provides a multi piece primer insert for ammunition comprising: an upper primer insert portion comprising an upper primer aperture through an upper primer bottom surface; a substantially cylindrical coupling element extending away from the upper primer bottom surface, and an interior surface; a lower primer insert portion comprising a lower primer bottom surface opposite a lower primer top surface, a primer recess in the lower primer top surface adapted to fit a primer, a lower primer aperture through the lower primer bottom surface, and a flange that adapted to receive a polymer overmolding extends circumferentially about an outer edge of the lower primer top surface; and an insert joint that links the upper primer bottom surface and the lower primer bottom surface to form a primer insert.

The present invention provides a subsonic ammunition including a polymeric casing body; a propellant insert positioned in the propellant chamber to reduce the internal volume of the propellant chamber; a propellant disposed and confined within the propellant chamber; a primer insert positioned at the body base and in communication with the propellant chamber; a primer and diffuser disposed in the primer insert in combustible communication with the propellant; and a projectile frictionally fitted in the mouth in combustible communication with the propellant.

The present invention provides a subsonic ammunition including a polymeric casing body; a propellant insert positioned in the propellant chamber to reduce the internal volume of the propellant chamber; a propellant disposed and confined within the propellant chamber; a primer insert positioned at the body base and in communication with the propellant chamber; a primer and diffuser disposed in the primer insert in combustible communication with the propellant; and a projectile frictionally fitted in the mouth in combustible communication with the propellant.

The present invention discloses a lightweight hybrid cartridge case (100) for a cartridged ammunition and a method of manufacture (200). The lightweight hybrid cartridge case (100) includes a cap (110) with a cylindrical sidewall (112) connected a base (120); a polymer shell (150) is insert-molded onto the sidewall of the cap; and an overmolded sleeve (180) is formed to cover the metal-polymer joint between the cap (110) and the polymer sleeve (150). The cylindrical sidewall (112) covered by the overmolded sleeve (180) has a plurality of stepped ridges (132, 132a), preferably with one stepped ridge (133) having a C-stepped edge (134).

The present invention discloses a lightweight hybrid cartridge case (100) for a cartridged ammunition and a method of manufacture (200). The lightweight hybrid cartridge case (100) includes a cap (110) with a cylindrical sidewall (112) connected a base (120); a polymer shell (150) is insert-molded onto the sidewall of the cap; and an overmolded sleeve (180) is formed to cover the metal-polymer joint between the cap (110) and the polymer sleeve (150). The cylindrical sidewall (112) covered by the overmolded sleeve (180) has a plurality of stepped ridges (132, 132a), preferably with one stepped ridge (133) having a C-stepped edge (134).

One embodiment of the present invention provides a making a polymeric ammunition having wicking texturing about the projectile end.