Delivery of projectiles from a rifled bore

Abstract

A 25 mm ammunition cartridge centered about a longitudinal axis and extending from a proximal end to a distal end including a case having a base defining the proximal end and a case sidewall extending from the base to a distal mouth and defining a case cavity, a propellant charge disposed in at least a portion of the case cavity, a body having a proximal cup and a body sidewall extending to a distal interface, wherein at least a proximal portion of the body is receivable in the case cavity distal to the propellant charge, a cap extending from a proximal cap portion coupled to the distal interface of the body to a dome defining the distal end of the cartridge, wherein the body and the cap define a projectile cavity, and one or more projectiles positioned within the projectile cavity.

What is claimed is: 
     
         1 . A cartridge of ammunition centered about a longitudinal axis and extending from a proximal end to a distal end, the cartridge comprising:
 a case having a base defining the proximal end and a case sidewall extending from the base to a distal mouth and defining a case cavity;   a propellant charge disposed in at least a portion of the case cavity;   a body having a proximal cup and a body sidewall extending to a distal interface, wherein at least a proximal portion of the body is receivable in the case cavity distal to the propellant charge;   a cap extending from a proximal cap portion coupled to the distal interface of the body to a dome defining the distal end of the cartridge, wherein the body and the cap define a projectile cavity; and   one or more projectiles positioned within the projectile cavity.   
     
     
         2 . The cartridge of  claim 1 , wherein the case has a diameter of at least 20 millimeters, wherein the base comprises at least one of percussion primer, a booster pellet, and a flash tube, and wherein at least a portion of the base defines an extractor ring. 
     
     
         3 . The cartridge of  claim 1 , wherein the propellant charge is configured to propel the one or more projectiles from a firearm with a muzzle velocity within a range from about 550 feet per second (ft/s) (168 meters per second (m/s)) to about 1400 ft/s (427 m/s). 
     
     
         4 . The cartridge of  claim 1 , further comprising at least one of an obturating ring and a driving band rotatably coupled to the body sidewall and, when discharged from a firearm, configured to engage a rifling of the firearm and decouple a spin rate of the body relative to the rifling. 
     
     
         5 . The cartridge of  claim 1 , further comprising at least one of an obturating ring and a driving band integrally formed with the body sidewall. 
     
     
         6 . The cartridge of  claim 1 , further comprising at least one of an obturating ring and a driving band disposed radially adjacent at least a first portion of the cap, wherein, when discharged from a firearm, at least one of the obturating ring and the driving band is configured to engaged with a rifling of a barrel of the firearm and translate a compressive force to the first portion of the cap to fracture or displace at least a second portion of the cap. 
     
     
         7 . The cartridge of  claim 1 , further comprising a sleeve defining a cylindrical annulus extending from a proximal sleeve portion radially adjacent to the proximal cup of the body to a distal sleeve portion engaged with the proximal cap portion. 
     
     
         8 . The cartridge of  claim 7 , wherein, when discharged from a firearm, in response to an axial force on the body, the sleeve is configured to translate axially in a proximal direction relative to the cap to disengage from the proximal cap portion. 
     
     
         9 . The cartridge of  claim 7 , wherein cartridge further comprises at least one of an obturating ring and a driving band integrally formed with or coupled to the sleeve. 
     
     
         10 . The cartridge of  claim 1 , wherein the proximal cup defines a distal facing surface having a curvature shaped to receive therein at least one of the one or more projectiles. 
     
     
         11 . The cartridge of  claim 1 , wherein the proximal cup defines a proximal facing surface configured to splay, when discharged from a firearm and in response to a pressure produced by the propellant charge, in a radial direction to seal propellant gases proximal to the body. 
     
     
         12 . The cartridge of  claim 1 , wherein the proximal cup comprises a proximally extending skirt configured to, when discharged from a firearm, splay in a radial direction. 
     
     
         13 . The cartridge of  claim 12 , wherein the proximally extending skirt extends from a plane normal to the longitudinal axis to a proximal edge a length within a range from about 0.250 inches (6.35 millimeters (mm)) to about 0.750 inches (19.05 mm). 
     
     
         14 . The cartridge of  claim 1 , wherein the body sidewall comprises at least one of a plurality of skives and a plurality of slits configured to, when discharged from a firearm, in response to at least one of an air-resistance and a pressure produced by the propellant charge, urge at least a portion of the body sidewall radially outward. 
     
     
         15 . The cartridge of  claim 1 , wherein the proximal cup defines an aperture configured to, when discharged from a firearm, in response to a propellant gas produced by the propellant charge, pass therethrough a portion of the propellant gas. 
     
     
         16 . The cartridge of  claim 1 , wherein the cap comprises a frangible material configured to, when discharged from a firearm, fracture to expose the one or more projectiles. 
     
     
         17 . The cartridge of  claim 1 , wherein the cap comprises one or more materials having a combined density configured to, when discharged from a firearm, enable the cap to contact or penetrate a target. 
     
     
         18 . The cartridge of  claim 1 , wherein the cap comprises two or more skives defining a two or more petals configured to, when discharge from a firearm, in response to at least one of an air-resistance and a centripetal force, radial separate to expose the one or more projectiles. 
     
     
         19 . The cartridge of  claim 1 , wherein the one or more projectiles comprises a plurality of projectiles configured to, when discharged by the propellant charge from a rifled barrel of a firearm, at a distance within a range from about 5 meters to about 40 meters, orient in a pattern having maximum distance between two projectiles of the plurality of projectiles of less than about 2 meter. 
     
     
         20 . The cartridge of  claim 1 , further comprising one or more projectile retainers disposed within the projectile cavity and configured to retain the one or more projectiles in a selected arrangement.