Polymer ammunition cartridge having a three-piece primer insert

1. A polymeric ammunition cartridge comprising:

a three 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, and a substantially cylindrical coupling element extending away from an upper primer top surface;

a groove formed by the difference in diameter between the upper primer aperture and a middle primer aperture, wherein the groove is adapted to receive a polymer overmolding;

a middle primer insert portion comprising a middle aperture and an upper joint of the middle primer insert portion positioned in contact with the upper primer bottom surface and adjacent to the groove, wherein the middle aperture is smaller than the upper primer aperture; and a lower primer insert portion in contact with the middle primer insert portion comprising a lower primer bottom surface in contact with a lower joint of the middle primer insert portion and 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 aperture through the lower primer bottom surface, wherein the lower aperture is smaller than the middle aperture;

a substantially cylindrical polymeric middle body extending about the three piece primer insert, wherein the substantially cylindrical polymeric middle body comprises:

a substantially cylindrical polymeric bullet-end coupling element at a first end of the substantially cylindrical polymeric middle body opposite a substantially cylindrical polymeric coupling end connected by a powder chamber, wherein the substantially cylindrical polymeric coupling end extends over the substantially cylindrical coupling element and into the groove; and

a substantially cylindrical polymeric bullet-end upper portion comprising a bullet-end coupling element connected to the substantially cylindrical polymeric bullet-end coupling element opposite a projectile aperture adapted to engage a bullet.

2. The polymeric ammunition cartridge of claim 1 wherein the polymeric ammunition cartridge has a caliber selected from .223, .243, .25-06, .270, .300, .308, .338, .30-30, .30-06, .45-70 or .50-90, 50 caliber, 45 caliber, 380 caliber or 38 caliber, 5.56 mm, 6 mm, 7 mm, 7.62 mm, 8 mm, 9 mm, 10 mm, or 12.7 mm.

3. The polymeric ammunition cartridge of claim 1 wherein the polymeric ammunition cartridge has a caliber selected from .308, .338, 50 caliber, 5.56 mm, 7.62 mm, or 12.7 mm.

4. The polymeric ammunition cartridge of claim 1 , wherein the substantially cylindrical polymeric middle body is formed from a ductile polymer, a nylon polymer or a fiber-reinforced polymeric composite.

5. The polymeric ammunition cartridge of claim 1 , wherein the substantially cylindrical polymeric bullet-end upper portion comprises a ductile polymer, a nylon polymer or a fiber-reinforced polymeric composite.

6. The polymeric ammunition cartridge of claim 1 , wherein the substantially cylindrical polymeric middle body comprise a polymers selected from the group consisting of polyurethane prepolymer, cellulose, fluoro-polymer, ethylene inter-polymer alloy elastomer, ethylene vinyl acetate, nylon, polyether imide, polyester elastomer, polyester sulfone, polyphenyl amide, polypropylene, polyvinylidene fluoride or thermoset polyurea elastomer, acrylics, homopolymers, acetates, copolymers, acrylonitrile-butadinen-styrene, thermoplastic fluoro polymers, inomers, polyamides, polyamide-imides, polyacrylates, polyatherketones, polyaryl-sulfones, polybenzimidazoles, polycarbonates, polybutylene, terephthalates, polyether imides, polyether sulfones, thermoplastic polyimides, thermoplastic polyurethanes, polyphenylene sulfides, polyethylene, polypropylene, polysulfones, polyvinylchlorides, styrene acrylonitriles, polystyrenes, polyphenylene, ether blends, styrene maleic anhydrides, polycarbonates, allyls, aminos, cyanates, epoxies, phenolics, unsaturated polyesters, bismaleimides, polyurethanes, silicones, vinylesters, urethane hybrids, polyphenylsulfones, copolymers of polyphenylsulfones with polyethersulfones or polysulfones, copolymers of poly-phenylsulfones with siloxanes, blends of polyphenylsulfones with polysiloxanes, poly(etherimide-siloxane) copolymers, blends of polyetherimides and polysiloxanes, and blends of polyetherimides and poly(etherimide-siloxane) copolymers.

7. The polymeric ammunition cartridge of claim 1 , wherein the substantially cylindrical polymeric bullet-end upper portion comprise a polymers selected from the group consisting of polyurethane prepolymer, cellulose, fluoro-polymer, ethylene inter-polymer alloy elastomer, ethylene vinyl acetate, nylon, polyether imide, polyester elastomer, polyester sulfone, polyphenyl amide, polypropylene, polyvinylidene fluoride or thermoset polyurea elastomer, acrylics, homopolymers, acetates, copolymers, acrylonitrile-butadinen-styrene, thermoplastic fluoro polymers, inomers, polyamides, polyamide-imides, polyacrylates, polyatherketones, polyaryl-sulfones, polybenzimidazoles, polycarbonates, polybutylene, terephthalates, polyether imides, polyether sulfones, thermoplastic polyimides, thermoplastic polyurethanes, polyphenylene sulfides, polyethylene, polypropylene, polysulfones, polyvinylchlorides, styrene acrylonitriles, polystyrenes, polyphenylene, ether blends, styrene maleic anhydrides, polycarbonates, allyls, aminos, cyanates, epoxies, phenolics, unsaturated polyesters, bismaleimides, polyurethanes, silicones, vinylesters, urethane hybrids, polyphenylsulfones, copolymers of polyphenylsulfones with polyethersulfones or polysulfones, copolymers of poly-phenylsulfones with siloxanes, blends of polyphenylsulfones with polysiloxanes, poly(etherimide-siloxane) copolymers, blends of polyetherimides and polysiloxanes, and blends of polyetherimides and poly(etherimide-siloxane) copolymers.

8. The polymeric ammunition cartridge of claim 1 , wherein the substantially cylindrical polymeric bullet-end and the substantially cylindrical polymeric bullet-end upper portion are welded or bonded together.

9. The polymeric ammunition cartridge of claim 1 , wherein the projectile aperture further comprises a mechanical interlock adapted to mate to a groove on a bullet.

10. The polymeric ammunition cartridge of claim 1 , wherein the substantially cylindrical polymeric bullet-end coupling element is welded or bonded to the substantially cylindrical polymeric bullet-end upper portion.

11. The polymeric ammunition cartridge of claim 1 , wherein the upper primer insert portion, the middle primer insert portion, the lower primer insert portion or a combination thereof independently comprises a polymer, a metal, an alloy, or a ceramic alloy.

12. The polymeric ammunition cartridge of claim 1 , wherein the upper primer insert portion, the middle primer insert portion, the lower primer insert portion or a combination thereof comprise the same material or different materials.

13. The polymeric ammunition cartridge of claim 1 , wherein the upper primer insert portion, the middle primer insert portion, the lower primer insert portion or a combination thereof comprise different polymers, different metals, different alloys, or different ceramic compositions.

14. The polymeric ammunition cartridge of claim 1 , wherein the upper primer insert portion, the middle primer insert portion, the lower primer insert portion or a combination thereof are independently comprise steel, nickel, chromium, copper, carbon, iron, stainless steel or brass.

15. The polymeric ammunition cartridge of claim 1 , wherein the upper primer insert portion, the middle primer insert portion, the lower primer insert portion or a combination thereof comprise 102, 174, 201, 202, 300, 302, 303, 304, 308, 309, 316, 316L, 316Ti, 321, 405, 408, 409, 410, 415, 416, 416R, 420, 430, 439, 440, 446 or 601-665 grade stainless steel or Ti6Al4V.

16. The polymeric ammunition cartridge of claim 1 , wherein the middle body connection end is a male coupling element with a straight skirt interlock surface that tapers to a smaller diameter at the forward portion on the skirt tip to mate with a female coupling element of the substantially cylindrical polymeric bullet-end.