Polymer ammunition having a primer insert with a primer pocket groove

1. A polymeric ammunition cartridge comprising:

a primer insert comprising: a top surface opposite a bottom surface and a extraction flange that extends circumferentially about an outer edge of the top surface; a coupling element that extends from the bottom surface, wherein the coupling element is adapted to receive a polymer overmolding; a primer recess in the top surface that extends toward the bottom surface, wherein the primer recess comprises a recess bottom and a circular recess side wall; a primer flash aperture through the recess bottom that extends through the bottom surface, wherein the primer flash aperture is adapted to receive the polymer overmolding to form a flash hole; and one or more pads positioned on the recess bottom; a groove in the primer recess positioned around the primer flash aperture to extend at least partially over the recess bottom and adapted to receive the polymer overmolding;

a substantially cylindrical polymeric middle body extending about the primer insert, wherein the substantially cylindrical polymeric middle body comprises: a polymeric bullet-end coupling element at a first end opposite a polymeric coupling end connected by a propellant, wherein the polymeric coupling end extends over the coupling element and into the primer flash hole aperture and into the groove and around the one or more pads to form a flash hole; and

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

a propellant at least partially filling the propellant chamber;

a primer inserted into the primer recess, wherein the primer aligns with the one or more pads; and

a projectile frictionally fitted in the bullet-end aperture.

2. The polymeric ammunition of claim 1 , wherein the one or more pads comprise 3 pads.

3. The polymeric ammunition of claim 1 , wherein the one or more pads comprise 2-6 pads.

4. The polymeric ammunition of claim 1 , wherein the one or more pads are positioned to align with an anvil of the primer.

5. The polymeric ammunition of claim 1 , wherein the one or more pads are aligned to support an anvil of the primer.

6. The polymeric ammunition 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.

7. The polymeric ammunition of claim 1 , further comprising a diffuser positioned in the primer recess in contact with the primer and comprising a diffuser flash hole aligned with the primer flash hole.

8. The polymeric ammunition 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.

9. The polymeric ammunition of claim 1 , wherein the substantially cylindrical polymeric bullet-end upper portion and the substantially cylindrical polymeric middle body independently comprise a ductile polymer, a nylon polymer or a fiber-reinforced polymeric composite.

10. The polymeric ammunition 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.

11. The polymeric ammunition 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.

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

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

14. The polymeric ammunition 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.

15. The polymeric ammunition of claim 1 , wherein the primer insert comprises a polymer, a metal, an alloy, or a ceramic alloy.

16. The polymeric ammunition of claim 1 , wherein the primer insert comprises steel, nickel, chromium, copper, carbon, iron, stainless steel or brass.

17. The polymeric ammunition of claim 1 , wherein the primer insert comprises 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.