Patent ID: 9506735
Filing Date: 2016-11-29
CPC Classification: F42B,F42C

Claim Text:
1. A method of making an ammunition cartridge having a two piece primer insert comprising the steps of: forming a substantially cylindrical primer insert by providing 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 inside the substantially cylindrical coupling element; providing 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 that extends toward the lower primer bottom surface and adapted to fit a primer, a lower primer aperture through the lower primer bottom surface, and a flange that extends circumferentially about an outer edge of the lower primer bottom surface, wherein the flange is adapted to receive a polymer overmolding; aligning the upper primer bottom surface and the lower primer bottom surface to align the lower primer aperture with the upper primer aperture and forming an insert joint; linking the upper primer bottom surface and the lower primer bottom surface to form a primer insert; providing a primer flash hole aperture extending through the lower primer aperture and the upper primer aperture; providing a first polymer composition for molding a polymer ammunition cartridge; molding from the first polymer composition a substantially cylindrical polymeric middle body having the substantially cylindrical primer insert at a first end and a substantially cylindrical polymeric coupling region at a second end, wherein the first polymer composition extends over an outer surface of the substantially cylindrical primer insert over the flange and the first polymer composition extends over an interior surface of the substantially cylindrical coupling region into the primer flash hole aperture forming a flash hole, wherein the first polymer composition extends from the substantially cylindrical polymeric coupling region into the primer flash hole aperture; forming a substantially cylindrical polymeric bullet-end component from a second polymer composition comprising a bullet aperture opposite a polymeric bullet-end coupling that mates to the substantially cylindrical coupling region; and coupling the substantially cylindrical coupling region to the polymeric bullet-end coupling to form a propellant chamber that extends from the primer flash hole aperture to the bullet aperture.