Multi-Piece Polymer Ammunition, Cartridge and Components

A multi piece ammunition cartridge comprising:

• an primer insert comprising 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, a primer flash hole aperture positioned in the primer recess to extend through the bottom surface, and a groove positioned around the primer flash hole aperture in the primer recess;
• a middle body comprising a body extending from a body half lap junction to the primer insert, wherein the body is molded at least partially the primer insert by molding over the cylindrical coupling element and into the primer flash hole aperture and into the groove to form a primer flash hole;
• and
• a nose connected to the middle body, wherein the nose comprises a generally cylindrical neck having a projectile aperture at a first end;
• a shoulder comprising a shoulder top connected to the generally cylindrical neck that extends to a shoulder bottom;
• a nose junction positioned around the shoulder bottom, wherein the nose junction comprises a half lap junction having a groove adjacent to a skirt adapted to mate to the body half lap junction to form an ammunition cartridge, wherein a propellant chamber is formed between the projectile aperture and the primer flash hole.

A multi piece ammunition cartridge comprising:

• an primer insert comprising 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, a primer flash hole aperture positioned in the primer recess to extend through the bottom surface, and a groove positioned around the primer flash hole aperture in the primer recess;
• a middle body comprising a body extending from a body half lap junction to the primer insert, wherein the body is molded at least partially the primer insert by molding over the cylindrical coupling element and into the primer flash hole aperture and into the groove to form a primer flash hole;
• and
• a shortened neck having a projectile aperture at a first end, wherein the shortened neck is reduced by 25-100% of the neck height of a standard cartridge neck;
• a shoulder comprising a shoulder top connected to the shortened neck that extends to a shoulder bottom;
• a nose junction positioned adjacent to the shoulder bottom, wherein the nose junction comprises a half lap junction having a groove adjacent to a skirt adapted to mate to the body half lap junction to form an ammunition cartridge, wherein a propellant chamber is formed between the projectile aperture and the primer flash hole.

An ammunition cartridge having a reduced neck height comprising:

• a shortened neck having a projectile aperture, wherein the shortened neck is reduced by 25-100% of the neck height of a standard cartridge neck;
• a shoulder extending from the shortened neck to a cartridge side wall;
• and
• wherein the cartridge side wall extends from the shoulder to the base to form an interior propellant chamber;
• wherein the base comprises an extraction ring, a primer recess positioned in the base in communication with the propellant chamber through a flash hole that extends from the primer recess into the propellant chamber.