US Patent 9835427 Two-piece primer insert for polymer ammunition

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.