Subsonic polymeric ammunition cartridge

Abstract

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 at least 10% 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.

What is claimed is: 
     
         1 . A subsonic ammunition comprising:
 a polymeric casing body comprising   a primer insert comprising a coupling region opposite a bottom surface, a primer recess in the bottom surface, and a primer flash aperture in the primer recess extending through the bottom surface;   a first end and a second end connected by a propellant chamber, wherein the first end is molded over the coupling region of the primer insert and into a primer flash aperture to form a flash hole, and   a second end opposite the first end and connected by a propellant chamber, wherein the second end comprises an aperture;   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 reduced by between 25 and 80%;   a propellant disposed and confined within the propellant chamber;   a primer disposed in the primer insert in combustible communication with the propellant; and   a projectile frictionally fitted in the mouth in combustible communication with the propellant.   
     
     
         2 . The subsonic ammunition of  claim 1 , wherein the internal volume that is about 25.1, 26, 27, 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, or 80% less than the open internal volume of a standard casing of equivalent caliber. 
     
     
         3 . The subsonic ammunition cartridge of  claim 1 , wherein the primer insert is overmolded into the polymeric casing body. 
     
     
         4 . The subsonic ammunition of  claim 1 , wherein the projectile does not exceed the velocity of 1200 feet per second at sea level under standard atmospheric conditions when fired. 
     
     
         5 . The subsonic ammunition of  claim 1 , wherein the projectile does not exceed the velocity of 1086 feet per second at standard atmospheric conditions when fired. 
     
     
         6 . The subsonic ammunition of  claim 1 , wherein the projectile is secured to the mouth by a mechanical interference, an adhesive, an ultrasonic welding, or a hot crimping. 
     
     
         7 . The subsonic ammunition of  claim 1 , wherein the polymer body comprises a material selected from the group consisting of polyphenylsulfone, polycarbonate, and polyamide. 
     
     
         8 . The subsonic ammunition 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 of  claim 1 , wherein the propellant insert has a substantially cylindrical shape. 
     
     
         10 . The subsonic ammunition of  claim 1 , wherein the propellant insert has a free formed shape. 
     
     
         11 . The subsonic ammunition of  claim 1 , wherein the propellant insert has a one or more ribs extending into the propellant chamber. 
     
     
         12 . The subsonic ammunition 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 of  claim 1 , wherein the radial cross-section of the propellant chamber is irregular along its longitudinal length. 
     
     
         14 . The subsonic ammunition of  claim 1 , wherein the radial size of the propellant chamber tapers along its longitudinal direction. 
     
     
         15 . The subsonic ammunition of  claim 1 , wherein the polymeric casing body and propellant insert are formed of different polymeric materials. 
     
     
         16 . The subsonic ammunition of  claim 1 , wherein the polymeric casing body and propellant insert are formed of the same polymeric materials. 
     
     
         17 . The subsonic ammunition of  claim 1 , wherein the polymeric casing body comprises 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. 
     
     
         18 . The subsonic ammunition of  claim 1 , wherein the propellant insert comprises 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. 
     
     
         19 . A subsonic ammunition case comprising:
 a polycarbonate casing body comprising a generally cylindrical hollow polycarbonate body having   a primer insert comprising a coupling region opposite a bottom surface, a primer recess in the bottom surface, and a primer flash aperture in the primer recess extending through the bottom surface;   a body base comprising a first end that extends to a second to form a propellant chamber there between, wherein the first end is molded over the coupling region of the primer insert and into a primer flash aperture to form a flash hole, and the second end comprises aperture; and   a circular 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, wherein the circular propellant insert comprises polycarbonate.