Multi-piece polymer ammunition, cartridge and components

A multi piece ammunition cartridge having a projectile with standard dimensions for that caliber of projectile, the multi-piece ammunition cartridge comprising:

• a 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 comprising a shortened neck having a projectile aperture at a first end and connected to a shoulder at an opposite end, wherein the shortened neck is reduced to a height less than a standard cartridge neck height;
• the 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.