Subsonic polymeric ammunition cartridge
The present invention provides a subsonic ammunition cartridge including a polymeric casing body comprising a generally cylindrical hollow polymer body having a body base at a first end thereof and a mouth at a second end to define a propellant chamber; a propellant insert positioned in the propellant chamber to reduce the internal volume of the propellant chamber, wherein the propellant chamber has an internal volume that is between 25 and 80% less than the open internal volume of a standard casing of equivalent caliber; and a primer insert positioned at the body base and in communication with the propellant chamber.
1. A subsonic ammunition cartridge comprising:
a primer insert comprises a top surface opposite a bottom surface; a substantially cylindrical coupling element extending away from the bottom surface forming and an exterior surface; a primer recess in the top surface that extends toward the bottom surface, a primer flash aperture positioned in the primer recess to extend through the bottom surface, a groove in the primer recess that extends circumferentially about the primer flash aperture and a flange that extends circumferentially about an outer edge of the top surface;
a polymeric casing body comprising a generally cylindrical hollow polymer body molded over the substantially cylindrical coupling element, into the primer flash aperture and into the groove and extending toward a case mouth to form a propellant chamber; and
a propellant insert positioned in the propellant chamber to reduce the internal volume of the propellant chamber by between 25 and 80%.
2. The subsonic ammunition cartridge of claim 1 , wherein the internal volume that is about 25.1, 25.2, 25.3, 25.4, 25.5, 25.6, 25.7, 25.8, 25.9, 26.0, 26.25, 26.5, 26.75, 27, 27.5, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80% or incremental variations thereof less than the open internal volume of a standard casing of equivalent caliber.
3. The subsonic ammunition cartridge of claim 1 , wherein the internal volume houses a propellant to propel a projectile to a velocity of less than 1200 feet per second at sea level under standard atmospheric conditions when fired.
4. The subsonic ammunition cartridge of claim 1 , wherein the internal volume houses enough of a propellant for a projectile to exceed the velocity of 1086 feet per second at standard atmospheric conditions when fired.
5. The subsonic ammunition cartridge of claim 1 , wherein the polymer body comprises a material selected from the group consisting of polybutylene terephthalate (PBT), polyphenylsulfone, polycarbonate, and polyamide.
6. The subsonic ammunition cartridge of claim 1 , wherein the polymeric casing body comprises a polymers selected from the group consisting of polybutylene terephthalate (PBT), 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 subsonic ammunition cartridge of claim 1 , wherein the propellant insert comprises a polymers selected from the group consisting of polybutylene terephthalate (PBT), 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 subsonic ammunition cartridge of claim 1 , further comprising at least one additive selected from the group consisting of plasticizers, lubricants, molding agents, fillers, thermo-oxidative stabilizers, flame-retardants, coloring agents, compatibilizers, impact modifiers, release agents, reinforcing fibers and reinforcing agents.
9. The subsonic ammunition cartridge of claim 1 , wherein the propellant insert has a substantially cylindrical shape.
10. The subsonic ammunition cartridge of claim 1 , wherein the propellant insert has a free formed shape.
11. The subsonic ammunition cartridge of claim 1 , wherein the propellant insert has a one or more ribs extending into the propellant chamber.
12. The subsonic ammunition cartridge of claim 1 , wherein the propellant insert has a radial cross-section selected from the group consisting of circular, ovoid, octagonal, hexagonal, triangular, star, ribbed, square and a combination thereof.
13. The subsonic ammunition cartridge of claim 1 , wherein the radial cross-section of the propellant chamber is irregular along its longitudinal length.
14. The subsonic ammunition cartridge of claim 1 , wherein the radial size of the propellant chamber tapers along its longitudinal direction.
15. The subsonic ammunition cartridge of claim 1 , wherein the polymeric casing body and propellant insert are formed of different polymeric materials.
16. The subsonic ammunition cartridge of claim 1 , wherein the polymeric casing body and propellant insert are formed of the same polymeric materials.
17. The subsonic ammunition cartridge of claim 1 , wherein the propellant chamber is formed of a separate propellant insert disposed within the internal cavity of the generally cylindrical hollow polymer body.