DELIVERY OF PROJECTILES FROM A RIFLED BORE

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a bypass continuation of PCT/US2025/015970, filed Feb. 14, 2025, titled DELIVERY OF PROJECTILES FROM A RIFLED BORE, which claims the benefit of U.S. Provisional Application No. 63/554,042, titled DELIVERY OF PROJECTILES FROM A RIFLED BORE, filed Feb. 15, 2024, the contents of which are expressly incorporated by reference herein.

TECHNICAL FIELD

The present invention is directed to cartridges for precision grenadier systems having projectiles with a selected fragment size, velocity, pattern distribution, and other predetermined characteristics.

BACKGROUND

Advancements in ammunition for precision grenadier systems have improved the capabilities and reliability of these weapons to engage defiladed positions, unmanned aerial systems, light armored vehicles, and door breaches. For example, improvements in propellant technology have led to the development of higher-velocity rounds, enhancing both range and accuracy. Additionally, improvements in projectile design, such as aerodynamic shaping and advanced materials, have increased terminal ballistics and penetration capabilities against a variety of targets. Overall, these advancements in precision grenadier systems ammunition technology have significantly enhanced the lethality and versatility of precision grenadier systems in modern combat scenarios.

SUMMARY

Precision grenadier systems are configured to deliver a payload to a target at a range up to about 1,000 meters using about 30,000 pounds per square inch (psi) of propellant pressure, with a relatively short rifled barrel (e.g., less than 18-inch barrel or less than 34 inches overall length) which may include titanium or its alloys. Generally, precisions grenadier systems must include robust platforms suitable for passing drop tests, water or debris intrusion, radiation exposure, or the like while maintaining operational capabilities. Although precisions grenadier systems have improved capabilities and reliability in some applications, there remains a need to enable or improve engagement of close combat targets. Close combat target rounds are capable of delivering lethal effects to exposed personnel targets within a range of less than about 75 meters.

The present disclosure describes ammunition cartridges for precision grenadier systems and other medium caliber armaments, including portable, semi-automatic, magazine-fed integrated armament systems. The disclosed ammunition cartridges are configured to deliver to a target at a range of at least 35 meters, such as at least 75 meters, projectiles having a selected size, velocity, and pattern distribution. In this way, the present disclosure provides for ammunition cartridges suitable for engagement of close combat targets.

The ammunition cartridges described herein are distinct from ammunition for shotguns at least in that the described ammunition cartridges include robust payloads for discharge at pressures exceeding 30,000 psi, suitable for use in rifled barrels, a dome distal end to facilitate reliable loading for semi-automatic operation, having a caliber equal to or greater than about 20 mm, and the like. Conversely, shotgun ammunition is generally configured for operation in smooth bore barrels at pressures less than 20,000 psi, having a planar distal end, and a caliber less than 20 mm.

In some examples, the disclosure describes an ammunition cartridge centered about a longitudinal axis and extending from a proximal end to a distal end. The cartridge includes a case, a propellant, a body, a cap, and one or more projectiles. The case includes a base defining the proximal end of the cartridge and a case sidewall extending from the base to a distal mouth and defining a case cavity. The propellant charge is disposed in at least a portion of the case cavity and configured to deliver the projectiles to a target. The body includes a proximal cup and a body sidewall extending to a distal interface. At least a proximal portion of the body is receivable in the case cavity distal to the propellant charge. The cap extends from a proximal cap portion coupled to the distal interface of the body to a dome defining the distal end of the cartridge. The body and the cap define a projectile cavity. The one or more projectiles are positioned within the projectile cavity.

In some examples, the case is a steel case having a diameter of 25 millimeters and the base houses at least one of a percussion primer, a booster pellet, and a flash tube. This enables the cartridge to be fired from a precision grenadier system. Additionally, or alternatively, at least a portion of the base may define an extractor ring configured to provide for semi-automatic operation of a firearm and feed from a magazine.

In some examples, the propellant charge is configured to propel the at least the one or more projectiles from a firearm with a muzzle velocity within a range from about 700 fect per second (ft/s) (213 meters per second (m/s)) to about 1,600 ft/s (488 m/s). In other examples, the muzzle velocity may be less than about 1,116 ft/s, thereby providing for a subsonic projectile which may reduce or prevent determination of shooter position based on acoustic characteristics of the one or more projectiles.

In some examples, the cartridge includes at least one of an obturating ring and a driving band. The obturating ring and/or the driving band may be integrally formed with the body sidewall, directly coupled to the body sidewall, or rotatable coupled to the body sidewall. The obturating ring and/or driving band may be disposed adjacent to an exterior surface of the body sidewall to provide for sealing of propellent gases, engagement of barrel rifling, or both. The obturating ring and/or the driving band may be rotatably coupled to the body sidewall such that, when discharged from a firearm, the is obturating ring and/or the driving band may at least partially engage a rifling of the firearm but may not fully transmit rotation to the body thereby decoupling a spin rate of the body relative to the rifling. In this way, the spin rate of the body when discharged from the barrel may be controlled.

In some examples, the obturating ring and/or the driving band is disposed radially adjacent at least a first portion of the cap such that, when discharged from a firearm, the obturating ring and/or the driving band may engage 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. In this way, upon firing, the cartridge may be configured to reliably fracture a select portion of the cap to provide for predicable separation of the cap and one or more projectiles as well as patterning of the one or more projectiles.

Additionally, or alternatively, the cartridge may include 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. Optionally, the sleeve may define or be coupled with an obturating ring and/or a driving band. When discharged from a firearm, in response to an axial force on the body, the sleeve may be configured to translate axial in the proximal direction relative to the cap to disengage from the proximal cap portion. In this way, upon firing, the cartridge may be configured to reliably provide for predicable separation of the cap and one or more projectiles as well as patterning of the one or more projectiles.

In some examples, the proximal cup defines a distal facing surface having a curvature shaped to receive therein at least one of the one or more projectiles. The curved surface may reduce or prevent movement of the one or more projectiles, for example, during discharge from a firearm, thereby providing for a more reliable patterning compared to a proximal cup with a planar distal facing surface.

In some examples, the proximal cup defines a proximal facing surface configured to, when discharged from a firearm, in response to a pressure produced by the propellant charge, splay in a radial direction to seal propellant gases distal of the body. Additionally, or alternatively, the proximal cup, e.g., the proximal facing surface, may include a proximally extending skirt configured to, when discharged from a firearm, splay in the radial direction. The skirt may extend from a plane normal to the longitudinal axis and extending through a proximal end of the projectile cavity to a proximal edge a length within a range from about 0.750 inches (1.91 centimeters (cm)) to about 0.800 inches (20.32 cm). The length of the skirt may be selected to provide engagement with rifled barrel of a firearm to cause a first spin of the body in a first circumferential direction.

In some examples, the cartridge may be configured to discharge from a firearm having a rifled barrel and a counter-rotating muzzle device. The rifled barrel may have any suitable twist rate, such as a 1×25″ twist rate. The counter-rotating muzzle device may have a similar twist rate (opposite that of the rifled barrel) or a gain twist. A bore of the counter-rotating muzzle may be greater than a bore of the rifled barrel such that the rifled barrel may impart on a first ammunition type a first spin rate and the combination of the rifled barrel and the counter-rotating muzzle device may impart on a second ammunition type a second spin rate that is less than the first spin rate. For example, when discharged from a firearm having a counter-rotating muzzle device, at least a portion of the described cartridges, such as a obturating ring, a driving band, a portion of the body, or a skirt of the body, may be configured to engage a counter-rotating muzzle device of a firearm to at least one of partially despin of the body or cause a second spin of the body in a second, opposing circumferential direction. In these ways, a counter-rotating muzzle device and engagement therewith by features of a cartridge may be used to control a spin rate.

In some examples, the body sidewall includes at least one of a plurality of skives, a plurality of slits, or other features that, when discharged from a firearm, and in response to an air-resistance on the body sidewall and/or a pressure produced by the propellant, urge at least a portion of the body sidewall radially outward. The portions of the body sidewall may project distally, proximally, or combinations thereof. The projecting portions of the body sidewall may provide a predicable distance of travel of the body with the projectiles before separation of the body from the projectiles.

In some examples, the proximal cup includes an aperture configured to, when discharged from a firearm, in response to a propellant gas produced by the propellant, pass therethrough a portion of the propellant gas. The aperture may include a valve configured to close in response to a threshold pressure. Also, the cartridge may include an elongate tube extending from a proximal end fluidly coupled to the aperture to a distal end disposed adjacent to the cap, such that the elongate tube is configured to, when discharged from a firearm, in response to a propellant gas produced by the propellant, pass therethrough a portion of the propellant gas to rupture or displace relative to the body at least a portion of the cap. By controllably venting a portion of the propellant gas into the projectile cavity, the cartridge may be configured to rupture, fracture, or otherwise displace at least a portion of the cap to facilitate predicable separation of the one or more projectiles from the body.

In some examples, the cap may include a frangible material configured to, when discharged from a firearm, fracture to expose the one or more projectiles. The frangible material defines at least part of the proximal cap portion to facilitate disengagement of the cap from the body. The frangible material of the cap may be configured to fracture in response to a force, such as a pressure produced from a propellant, friction of the payload with a barrel, air-resistance, centripetal force, or the like. Fracture of a frangible cap may be configured to facilitate separation of projectiles for a payload. In this way, materials may be selected to control or improve performance of the cartridge, such as patterning or range of projectiles.

In some examples, the cartridge may include one or more projectile retainers disposed within the projectile cavity and configured to retain the one or more projectiles in a selected special arrangement. The retainers may include a metal or polymeric cage or baffles defining at least one axial extending support and at least one radially extending support. Additionally, or alternatively, the retainers may include at least one circumferentially extending support. The retainers are configured to constrain the one or more projectiles in at least one of an axial direction, a circumferential direction, and a radial direction. In some examples, the retainers may resist centripetal forces when discharge from a firearm, thereby providing improved control of projectile pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure can be understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings.

FIG. 1 is a conceptual diagram illustrating an example firearm system.

FIGS. 2A and 2B are conceptual diagrams illustrating an example ammunition cartridge.

FIGS. 3A through 3L are conceptual diagrams illustrating an example ammunition cartridge with a cap having distal opening skives.

FIGS. 4A through 4M are conceptual diagrams illustrating an example ammunition cartridge with a cap having proximal opening skives and a driving band.

FIGS. 5A through 5L are conceptual diagrams illustrating an example ammunition cartridge with a frangible cap.

FIGS. 6A through 6G are conceptual diagrams illustrating an example ammunition cartridge with a frangible cap with an inertial weight for fracturing the cap.

FIGS. 7A through 7J are conceptual diagrams illustrating an example ammunition cartridge having a sleeve releasably coupled to a cap.

FIGS. 8A through 8J are conceptual diagrams illustrating an example ammunition cartridge having a frangible cap with a body positioned to fracture the cap.

FIGS. 9A through 9I are conceptual diagrams illustrating an example ammunition cartridge having a body with a burst hole to fracture a frangible cap.

FIGS. 10A through 10D are conceptual diagrams illustrating an example projectile retainer of an ammunition cartridge.

FIGS. 11A through 11F are conceptual diagrams illustrating an example ammunition cartridge having a body with crushable portion.

FIGS. 12A through 12F are conceptual diagrams illustrating an example ammunition cartridge having a polymer front hinge.

FIGS. 13A and 13B are conceptual diagrams illustrating an example counter-rotation muzzle device.

DETAILED DESCRIPTION

For purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nonetheless be understood that no limitation of the scope of the disclosure is intended by the illustration and description of certain embodiments of the disclosure. In addition, any alterations and/or modifications of the illustrated and/or described embodiment(s) are contemplated as being within the scope of the present disclosure. Further, any other applications of the principles of the disclosure, as illustrated and/or described herein, as would normally occur to one skilled in the art to which the disclosure pertains, are contemplated as being within the scope of the present disclosure.

FIG. 1 is a conceptual diagram illustrating an example firearm system 100. Firearm system 100 includes a stock 102, a receiver 104, optics 106, a rifled barrel 108, counter-rotating muzzle device 110, piston grip 112, trigger 114, magazine 116, and ammunition cartridge 118. In some examples, firearm system 100 may include fewer components, additional components, or alternative components.

Firearm system 100 may be configured to fire any suitable caliber of ammunition cartridge 118, such as, for example, small caliber cartridges having a caliber less than about 20 millimeters (mm) or medium caliber having a caliber within a range from about 20 mm to about 57 mm. In some examples, firearm system 100 may include an autocannon, a grenade launcher, a precision grenadier system, or other medium caliber armament. Firearm system 100 may be a portable system configured to single operator use in combat scenarios.

Stock 102 is configured to enable an operator to brace and aim firearm system 100. For example, a single operator may be suitable to aim and discharge firearm system 100. Stock 102 may be removable or excluded, such that firearm system 100 may be coupled to a second firearm or a mounting device.

Receiver 104 may include components configured to facilitate operation, such as semi-automatic operation, of firearm system 100. Receiver 104 may house action components such as, for example, a hammer, a bolt, a breechblock, a firing pin, an extractor, a safety, and the like.

Optics 106 includes one or more devices suitable to aim firearm system 100. For example, optics may include one or more of iron sights, telescopic sights, holographic sights, laser sights, variable magnification, or the like. In some examples, optics 106 include optoelectronics which are configured to facilitate acquisition or engagement of a target, including, but not limited to, integrated rangefinder, wind sensor, acoustic sensor, ballistic support devices, augmented reality or digital overlay, or the like.

Rifled barrel 108 is configured to receive therethrough a payload of cartridges 118. For example, rifled barrel 108 defines a bore corresponding to a caliber of the payload of cartridge 118. Rifled barrel 108 may include any suitable rifling, such as, for example, a 1×25″ twist rate (e.g., pitch). In some examples, at least a portion of rifled barrel 108 may include a smooth bore, a gain twist, or other barrel features.

Counter-rotating muzzle device 110 is configured to despin or counter spin the payload of cartridge 118 before the payload exits firearm system 100. In some examples, counter-rotating muzzle device 110 may define a bore having rifling that opposes the rifling of rifled barrel 108. In the case of a clockwise rifling of rifled barrel 108, counter-rotating muzzle device 110 may include a counterclockwise rifling. The rifling of counter-rotating muzzle device 110 may include any suitable rifling, such as, for example, a 1×25″ twist rate. In some examples, counter-rotating muzzle device 110 may have a gain twist that starts at a low or zero twist rate with progressively greater twist rate until a final twist rate at the muzzle. The low or zero twist rate may reduce instantaneous spin direction change and/or possible stripping of portions of the payload.

In some examples, the bore diameter of counter-rotating muzzle device 110 may be greater than a bore diameter of rifled barrel 108. The difference in diameter may enable a first ammunition type (e.g., for which a spin rate imparted by rifled barrel 108 is desired) to be discharged from firearm system 100 without engagement of the counter-rotating muzzle device 110, and enable a second ammunition type (e.g., for which a spin rate imparted by rifled barrel 108 is less desired) having as playable portion to engage the counter-rotating muzzle device 110. The first ammunition may include a high explosive fused round having a rigid outer surface. In some examples, the difference in bore diameter of the rifled barrel 108 and the counter-rotating muzzle device 110 may be within a range from about 0.010 inches (0.254 mm) to about 0.050 inches (1.27 mm). The difference in bore diameter may be selected, in some examples, to limit a maximum yaw of a rigid round within the counter-rotating muzzle device 110 to less than about 10 degrees, such as less than about 5-degress.

In some examples, counter-rotating muzzle device 110 may define a muzzle brake configured to reduce recoil. In some examples, the muzzle brake defined by counter-rotating muzzle device 110 may be configured to produce a selected flaring of at least a portion of the payload of cartridge 118 as it exists the muzzle, as discussed in further detail below.

Piston grip 112 is configured to enable one-handed actuation of trigger 114. In some examples, piston grip 112 and trigger 114 (as well as features of receiver 104) may be configured for or reconfigurable to accommodate ambidextrous operation of firearm system 100.

Magazine 116 is configured to protect and retain cartridges 118, as well as to facilitate semi-automatic operation of firearm system 100. Magazine 116 may be configured to retain any suitable number of cartridges 118, such as two cartridges, five cartridges, ten cartridges, or more. In some examples, magazine 116 may be configured to single hand removal or insertion.

Cartridges 118 may include any suitable caliber and shape. Cartridge 118 includes a domed distal end to facilitate translation of cartridge 118 from magazine 116 into a chamber of receiver 104 during semi-automatic operation of firearm system 100. Cartridge 118 also includes an extractor ring to facilitate extraction of a spent cartridge after discharge of a payload. In some examples, cartridge 118 may include a plurality of projectiles for engagement of close combat targets, as discussed is further detail below.

FIGS. 2A and 2B are conceptual diagrams illustrating an example cartridge 200. Cartridge 200 is centered about a longitudinal axis 202 and extends from a proximal end 204 to a distal end 206. Cartridge 200 includes a case 208, a propellant charge 210, and a payload 212. Payload 212 may include a body 214 and a cap 216 defining a projectile cavity 217 housing one or more projectiles 218, and an optional sleeve 220 and optional obturating ring or driving band 221. Cartridge 200 may include fewer features, additional features, or alternative features.

Case 208 includes a base 222 defining proximal end 204 and a case sidewall 224 extending from base 222 to a distal mouth 226 and defining a case cavity 228. Case 208 may include any suitable material. In some examples, case 208 may include steel, aluminum, brass, polymeric materials, thermoplastics, thermoset plastics, polycarbonate, polyamide, nylon, or the like. Polymeric materials may be preferred to reduce the weight of cartridge 200, with thermoplastics being more suitable for molding processes relative to thermoset plastics. Base 222 defines an aperture configured to receive a percussion primer 223 that may be operatively coupled to an ignition device 225, such as a booster pellet or a flash tube. At least a portion of the base defines an extractor ring 227 configured to facilitate extraction of case 208 from a chamber of a firearm system after discharge of payload 212.

In some examples, distal mouth 226 of case 208 may be coextensive with at least a portion of payload 212 or nearly or completely enclose payload 212. For example, distal mouth 226 may terminate along any portion of body 214 or cap 216 or may extend a full length of cartridge 200 and at least partially encapsulated cap 216 at a hemispherical crimp. In some examples, by extending the full length of cartridge 200, case 208 may provide additional protection to payload prior to firing, facilitate semiautomatic feeding or chambering of cartridge 200, or both.

Case 208 may have a diameter of at least 20 mm, such as at least 25 mm or at least 30 mm. The diameter of case 208 may be selected to receive, within at least a portion of case cavity 228, a portion of payload 212 having a caliber equal to or greater than 20 mm, such as a 25 mm caliber, a 30 mm caliber, a 40 mm caliber, or a 50 mm caliber.

Propellant charge 210 is disposed in at least a portion of case cavity 228. In some examples, an amount of propellant charge 210 may be selected to control a muzzle exit energy of payload 212. For example, muzzle exit energy may be selected to be within a range from about 1800 foot-pounds to about 2000 foot-pounds, such as about 1939 foot-pounds. Muzzle exit energy may be correlated to, based on a mass of payload 212, a recoil force, a muzzle exit velocity of payload 212, or both. In some examples, a muzzle exit velocity may be selected 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) For example, Table 1 illustrates example muzzle exit velocity of selected masses of payload 212 at a muzzle exit energy of about 1939 foot-pounds.

Body 214 includes a proximal cup 230 and a body sidewall 232 extending to a distal interface 234. At least a proximal portion 236 of body 214 is receivable in case cavity 228 distal to propellant charge 210. Proximal cup 230 defines a distal facing surface 238 (also referred to as a shot cup) and a proximal facing surface 240 (also referred to as a propellant cup).

Distal facing surface 238 is configured to retain projectiles 218 and may define a curvature shaped to receive therein at least one of projectiles 218. By receiving at least one of projectiles 218, distal facing surface 238 may reduce movement of projectiles 218 or deformation of proximal cup 230 during discharge, either or both of which may provide a more stabile trajectory of payload 212.

Proximal facing surface 240 may be configured to, when discharged from a firearm, in response to a pressure produced by propellant charge 210, splay in a radial direction (as indicated by arrow R) to seal propellant gases proximal of body 214. This sealing of propellant gases may provide a greater muzzle exit energy per unit (e.g. mass or volume) of propellant charge 210 compared to a body that is not configured to radially splay. Additionally, or alternatively, the radially splayed portion of proximal facing surface 240 may contact or otherwise interact with rifling of a barrel (e.g., rifled barrel 108), counter-rotation muzzle device (e.g., counter-rotating muzzle device 110), or both to cause a spin of payload 212 as it travels through the barrel and/or muzzle device.

In some examples, proximal cup 230 (e.g., proximal facing surface 240) may include a proximally extending skirt 242. Skirt 242 is optional. Skirt 242 is configured to, when discharged from a firearm and/or in response to a pressure produced by the propellant charge, splay in the radial direction. Skirt 242 extends from a plane normal to the longitudinal axis and extending through a proximal end of projectile cavity 217 to a proximal edge a length within a range from about 0.750 inches (1.91 centimeters (cm)) to about 0.800 inches (20.32 cm).

In some examples, skirt 242 may include fins, pleats, folds, baffles, bellows, or other suitable features such as those described in U.S. Pat. Nos. 10,422,611; 9,879,957; 10,935,354; and D847,293; the entirety of each of which is incorporated by reference herein.

At least a portion of a splayed skirt 242 may contact or otherwise interact with rifling of a barrel (e.g., rifled barrel 108), counter-rotation muzzle device (e.g., counter-rotating muzzle device 110), or both to cause a spin of payload 212 as it travels through the barrel and/or muzzle device. In some examples, skirt 242 may be configured to engage a rifled barrel of a firearm to cause a first spin of the body in a first circumferential direction (e.g., a clockwise direction). Additionally, or alternatively, skirt 242 may be configured to engage a counter-rotating muzzle device of a firearm to at least one of partially despin payload 212 (e.g., body 214, cap 216, or sleeve 220) or cause a second spin of payload 212 in a second, opposing circumferential direction (e.g., a counterclockwise direction). After exiting a muzzle of a firearm, splayed skirt 242 may provide an air-resistance to facilitate predicable separation of body 214 from projectiles 218 and, thereby, provide for a predicable patterning of projectiles 218.

Although described as including a proximal facing skirt 242, in other examples, at least a portion of body 214 may define other features including distally facing hinged fins or flaps that, after exiting the muzzle, fully deploy to provide an air-resistance to facilitate predicable separation of body 214 from projectiles 218 and, thereby, to provide for a predicable patterning of projectiles 218. For example, body sidewall 232 may include 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, an inertia of projectile 218 against proximal cup 230, and a pressure produced by propellant charge 210, urge at least a portion of body sidewall 232 radially outward.

In some examples, proximal cup 230 may define at least one aperture configured to, when discharged from a firearm, in response to a propellant gas produced by propellant charge 210, pass therethrough a portion of the propellant gas from propellant cavity 228 to projectile cavity 217. In this way, projectile cavity 217 may be at least partially pressurized during discharge to produce a desired effect on body 214, cap 216, or both, as discussed in further detail below.

In some examples, the aperture may include a valve configured to close in response to a threshold pressure. For example, the threshold pressure may be 10,000 pounds per square inch (psi), 20,000 psi, or 30,000 psi. The threshold pressure may be selected based on the desired effect on body 214 or cap 216, such as a pressure required to fracture at least a portion of the cap.

In some examples, an elongate tube may be fluidly coupled to the aperture. The elongate tube may extend from a proximal end fluidly coupled to the aperture to a distal end disposed adjacent to cap 216. When discharged from a firearm, in response to a propellant gas produced by the propellant, the aperture and elongate tube may pass therethrough a portion of the propellant gas to rupture or displace relative to body 214 at least a portion of cap 216.

Cap 216 extends from a proximal cap portion 244 coupled to distal interface 234 of body 214 to a dome 246 defining distal end 206 of cartridge 200. Proximal cap portion 244 may define one or more protrusions or recesses that are configured to releasably engage one or more corresponding recesses or protrusions defined by distal interface 234. In some examples, proximal cap portion 244 may release or disengagement from distal interface 234 in response to an inertia of a portion of payload 212, a pressurization of projectile cavity 217, a compression of payload 212 imparted by a firearm barrel, an air-resistance, or a centripetal force.

Dome 246 may include any suitable shape. In some examples, a shape of dome 246 may be selected to facilitate translation of cartridge 200 from a magazine (e.g., magazine 116) into a chamber of a receiver 104 of a firearm. Additionally, or alternatively, a shape of dome 246 may be selected to provide a desired flight performance of payload 212. For example, dome 246 may define a suitable ogive, such as a tangent ogive, a secant ogive, of a hybrid ogive.

In some examples, cap 216 may include features configured to expose and separate from projectiles 218 during discharge from a firearm. For example, cap 216 may include 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 projectiles 218.

Cap 216 may include any suitable material. In some examples, cap 216 may include a frangible material configured to, when discharged from a firearm, fracture or otherwise degrade to expose projectiles 218. Frangible materials include, but are not limited to, a ceramic, a polymer, sintered metals, polystyrenes, nylon, high density polyethylene, polyester, polyether ether ketone, and the like. A frangible cap 216 may include features configured to facilitate fracture or degradation of cap 216, such as, for example, weighted structures, skives, ribs, or the like. In some examples, fragments of a frangible cap 216 may define projectiles.

In other example, cap 216 may include a metal, steel, copper, lead, aluminum, brass, or combinations thereof. A metal cap 216 may define a projectile when discharged from a firearm. For example, cap 216 may include one or more materials having a combined density configured to, when discharged from a firearm, enable cap 216 to contact or penetrate a target.

Projectiles 218 may include any suitable projectiles. Projectiles 218 may include pellets having a diameter within a range from about 0.08 inches (2.30 mm) to about 0.36 inches (9.14 mm) such as within a range from about 0.24 inches (6.10 mm) to about 0.36 inches (9.14 mm). In some examples, projectiles 218 may include shot, such as, e.g., #9, #8½, #8, #7½, #7, #6, or #5; or buck shot, such as #4 buck, #3 buck, #2 buck, #1 buck, #0 buck, #00 buck, or #000 buck. In some examples, projectiles 218 may include a plurality of projectiles having a two or more different diameters. The material of projectiles may include, but is not limited to, one or more transition metals, such as, iron, cobalt, nickel, copper, zinc, titanium, chromium, and tungsten; one or more post-transition metals or metalloids, such as, aluminum, indium, tin, antimony, arsenic, lead, bismuth; steel; gilding metals; and alloys or combinations thereof. In some examples, one or more materials of projectiles 18 may be selected to provide any suitable density of projectiles 18, such as a density of greater than about 7 grams per cubic centimeter (g/cc), or greater than about 11 g/cc, or greater than about 12 g/cc, or greater than about 18 g/cc. Projectiles 218 may include any suitable shape.

When discharged by propellant charge 210 from a rifled barrel of a firearm, at a distance within a range from about 5 meters to about 40 meters, such as a distance within a range from about 5 meters to about 30 meters or about 5 meters to about 15 meters, payload 212 may be configured to orient projectiles 218 in a pattern having maximum distance between two projectiles of projectiles 218 of less than about 2 meters, such as less than about 1 meter or less than about 0.5 meters.

In some examples, to secure and facilitate patterning of projectiles 218, payload 212 may include one or more projectile retainers. The projectile retainers are disposed within the projectile cavity and configured to retain the one or more projectiles in a selected special arrangement. For example, the projectile retainers may include a cage having at least one axial extending support, at least one radially extending support, and/or at least one circumferentially extending support. An axial extending support may be configured to constrain projectiles 218 in at least one of a circumferential direction and a radial direction. A radially extending support may be configured to constrain projectiles 218 in at least one of a circumferential direction and an axial direction. A circumferentially extending support may be configured to constrain the one or more projectiles in at least one of a radial direction and an axial direction.

Sleeve 220 defines a cylindrical annulus extending from a proximal sleeve portion radially adjacent to the proximal cup of body 214 to a distal sleeve portion engaged with the proximal cap portion 244. In some examples, when discharged from a firearm, in response to an axial force on the body, sleeve 220 is configured to translate axial in the proximal direction relative to cap 216 to disengage from the proximal cap portion.

Obturating ring or driving band 221 is configured to facilitate sealing of propellant gases between payload 212 and a firearm barrel. An obturating band may be freely rotatable about cartridge 200. A drive band may be configured to engage rifling of a barrel. In some examples, obturating ring or the driving band 221 is rotatably coupled to body sidewall 232 and, when discharged from a firearm (e.g., firearm system 100), is configured to engage a rifling of the firearm and decouple a spin rate of the body relative to the rifling. In some examples, at least one of the obturating ring and the driving band 221 is integrally formed with or coupled to at least one of body sidewall 232, cap 216, and sleeve 220. In some examples, at least one of obturating ring or driving band 221 is disposed radially adjacent at least a first portion of cap 216, such that, when discharged from a firearm, obturating ring or driving band 221 is configured to engage with a rifling of a barrel of the firearm and translate a compressive force to the first portion of cap 216 to fracture or displace at least a second portion of cap 216.

FIGS. 3A through 3L are conceptual diagrams illustrating an example ammunition cartridge 300 with a cap 316 having distal opening skives 350. Cartridge 300 may be the same as or substantially similar to cartridge 200 discussed above, except for the differences described herein. For example, cartridge 300 is centered about a longitudinal axis, extends from a proximal end to a distal end, and includes a case 308, a propellant charge, and a payload 312 having a body 314 and a cap 316 defining a projectile cavity 317 housing one or more projectiles 318.

Cap 316 may be integrally formed with body 314. Such unitary construction may improve manufacturability relative to a cartridge with more components.

Cap 316 and body 314 define four skives 350 extending from a proximal terminus 352 to a distal intersection 354. Skives 350 includes a region of thinner material relative to other portions of body 314 and cap 316. Proximal terminus 352 may include a tapering of skives 350 to a respective plane tangent to an exterior surface of body 314. Alternatively, proximal terminus 352 may include an abrupt termination of skive 350 or a circumferential skive extending around body 314. Distal intersection 354 may define an aperture exposed to projectile cavity 317 or include thinner portion of cap or a membrane, such as a polymer-based membrane. Each pair of adjacent skives 350 defines a petal 356 configured to facilitate a release of projectiles 318 when discharged from a firearm.

FIGS. 3I through 3L illustrate separation of body 314 and cap 316 from projectiles 318 when discharged from a firearm 390. When travelling through a rifled barrel of firearm 390, the rifling may cause the payload to spin in a clockwise direction (indicated by arrow S) (FIG. 3H).

Upon breeching the muzzle, cap 316 may experience an air-resistance (indicated by arrow A), a centripetal force (indicated by arrow C), or both (FIG. 3I).

The air-resistance and/or centripetal force may cause petals 356 to deform or fracture, at least initially, along skives 350 (FIG. 3J). In some examples, the centripetal force may cause at least a portion of projectiles 318 to move radially from a longitudinal axis of cartridge 300.

Once deformation or fracture begins, continued air-resistance and/or centripetal force may fully expose projectiles 318, which continue down range as body 314 and cap 316 is further slowed by continued air-resistance (FIG. 3L).

In other examples, body 314 and cap 316 may remain substantially consolidated until impact with a rigid object, which then causes frangible cap 316 to fracture.

FIGS. 4A through 4M are conceptual diagrams illustrating an example ammunition cartridge 400 with a cap having proximal opening skives 450 and a driving band 421. Cartridge 400 may be the same as or substantially similar to cartridge 200 and/or 300 discussed above, except for the differences described herein. For example, cartridge 400 is centered about a longitudinal axis, extends from a proximal end to a distal end, and may be coupled to a case having a propellant charge, and a payload 412 having an integral body 414 and cap 416 defining a projectile cavity 417 housing one or more projectiles 418.

Body 414 is coupled to a disc 431. Disc 413 may be similar to proximal cup 230 discussed above, except that it may separately formed and coupled to body 414. An interior surface of body 414 defines a plurality of axially extending skives 450, each pair of adjacent skives defining a respective petal 456. Although illustrated as defined by an interior surface, in other example, skives 450 may be defined by an exterior surface of body 414.

FIGS. 4H through 4M illustrate separation of disc 430 from body 414, and separation of body 414 and cap 416 from projectiles 418 when discharged from a firearm 490. When travelling through a rifled barrel of firearm 490, driving band 421 may engage the rifling and cause payload 412 to spin in a clockwise direction (indicated by arrow S) (FIG. 4H).

Upon breeching the muzzle, petals 456 defined by body 414 may experience a radially outward deflection from a centripetal force (indicated by arrow C) from the rotating mass of body 414, mass of projectiles 418, or both (FIG. 4I).

The centripetal force causes petals 456 to deform or fracture, at least initially, along skives 450 (FIG. 3J). Initial deformation of petals 456 may disengage disc 430. In some examples, the centripetal force may cause at least a portion of projectiles 418 to move radially from a longitudinal axis of cartridge 400 (FIG. 4K).

Deformation or fracture my progress until petals 456 are fully separated or projectiles 418 are fully exposed (FIG. 4L). In some examples, at least a portion of cap 416, or fragments of body 414, may continue down range with projectiles 418 (FIG. 4M). The portion of cap 416 or fragments of body 414 may define additional projectiles configured to contact a target.

FIGS. 5A through 5L are conceptual diagrams illustrating an example ammunition cartridge 500 with a frangible cap 516. Cartridge 500 may be the same as or substantially similar to cartridge 200, 300, and/or 400 discussed above, except for the differences described herein. For example, cartridge 500 is centered about a longitudinal axis, extends from a proximal end to a distal end, and may be coupled to a case having a propellant charge, and a payload 512 having a body 514 and a cap 516 defining a projectile cavity 517 housing one or more projectiles 518. The proximal portion of body 514 defines a skirt 542.

Cap 516 may be separately formed and coupled to body 514. For example, body 514 may define a recess 515 that is configured to receive therein and interlock with a protrusion 519 defined by cap 516. Although illustrated as an interlock ring-shaped recess and protrusion, in other examples, recess 515 may include a plurality of recesses and protrusion 519 may include a plurality of corresponding tabs. Additionally, or alternatively, body 514 may be coupled to cap 516 with an adhesive, by spin welding, staking, or the like.

Cap 516 defines four skives 550 extending from a proximal terminus 552 to a distal intersection 554, which may be the same or substantially similar to the skives 350, proximal terminus 352, and distal intersection 354 discussed above in reference to FIGS. 3A through 3L. Each pair of adjacent skives 550 defines a petal 556 configured to facilitate a release of projectiles 518 when discharged from a firearm.

FIGS. 5I through 5L illustrate separation of body 514 and cap 516 from projectiles 518 when discharged from a firearm 590. When travelling through a rifled barrel of firearm 590, the rifling may cause the payload to spin in a clockwise direction (indicated by arrow S) (FIG. 51). In some examples, a pressure (indicated by arrow P) produced by the propellant charge may contact the proximal portion of body 514 and urge skirt 542 radially outward. The urging of skirt 542 radially outward may cause skirt 542 to contact the rifled barrel to enhance sealing of propellant gases, engage rifling to cause rotation of body 514, or both.

Upon breeching the muzzle, cap 516 may experience an air-resistance (indicated by arrow A), a centripetal force (indicated by arrow C), or both (FIG. 5J). Additionally, a muzzle blast (indicated by arrow B) produced by the propellant gas may cause skirt 542 to flare radially outward.

The air-resistance and/or centripetal force may cause petals 556 of cap 516 to deform or fracture, at least initially, along skives 550 (FIG. 5K). In some examples, the centripetal force may cause at least a portion of projectiles 318 to move radially from a longitudinal axis of cartridge 500.

Once deformation or fracture begins, continued air-resistance with skirt 542 may slow body 514 while maintaining a trajectory better than a body 514 without a skirt (FIG. 5L). In this way, projectiles 518 may continue down range as body 514 slows, without a portion of body 514 altering the trajectory of individual projectiles. This may reduce fliers, i.e., one or more projectiles having an altered trajectory relative to the average trajectory of the other projectiles.

In other examples, body 514 and cap 516 may remain substantially consolidated until impact with a rigid object, which then causes frangible cap 516 to fracture.

FIGS. 6A and 6F are conceptual diagrams illustrating an example ammunition cartridge with a frangible cap with an inertial weight for fracturing the cap. Cartridge 600 may be the same as or substantially similar to cartridge 200, 300, 400, and/or 500 discussed above, except for the differences described herein. For example, cartridge 600 is centered about a longitudinal axis, extends from a proximal end to a distal end, and may be coupled to a case having a propellant charge, and a payload 612 having a body 614 and a cap 616 defining a projectile cavity 617 housing one or more projectiles 618. The proximal portion of body 614 defines a skirt 642.

Cap 616 may be separately formed and coupled to body 614, in the same or a substantially similar manner as discussed above in reference to body 514 and cap 516. Cap 616 defines four skives 650 extending from a proximal terminus 652 to a distal intersection 654, which may be the same or substantially similar to the skives 550, proximal terminus 552, and distal intersection 554 discussed above in reference to FIGS. 5A through 5L, except that distal intersection 654 includes a weight. Weighted distal intersection 654 may include a weight having a greater density relative to the material of the cap. For example, weighted distal intersection 654 may include lead, steel, polymer doped with a metal or relatively high-density material, a ceramic doped with a metal or a relatively high-density material, or the like. As used herein, a relatively high-density material may include a material that is denser than an adjacent material. In some examples, rather than including a weighted distal intersection, at least one projectile of projectiles 618 may be coupled to an internal portion of cap 616. For example, a steel shot pellet may be adhesively bonded to cap 616. Each pair of adjacent skives 650 defines a petal 656 configured to facilitate a release of projectiles 618 when discharged from a firearm.

FIGS. 6C through 6F illustrate separation of body 614 and cap 616 from projectiles 618 when discharged from a firearm 690. When propellant gases begin to accelerate the payload, an inertia (indicated as arrow I) may cause weighted distal intersection 654 to at least partially fracture cap 616 (FIG. 6C). When travelling through a rifled barrel of firearm 690, the rifling may cause the payload to spin in a clockwise direction (indicated by arrow S) (FIG. 6D). Cap 616 may, in some examples, continue to fracture or collapse inward toward projectile cavity 617. In some examples, body 614 may include a skirt 642 that may be urged by pressure P radially outward to enhance scaling of propellant gases, engage rifling to cause rotation of body 614, or both.

Upon breeching the muzzle, cap 616 may experience an air-resistance (indicated by arrow A), a centripetal force (indicated by arrow C), or both (FIG. 6E). Additionally, a muzzle blast (indicated by arrow B) produced by the propellant gas may cause skirt 642 to flare radially outward.

Continued air-resistance with skirt 642 may slow body 614 while maintaining a trajectory better than a body 614 without a skirt (FIG. 6F). Skirt 642 may include a plurality of fins (FIG. 6G). Projectiles 618 may continue down range as body 614 slows, without a portion of body 614 altering the trajectory of individual projectiles. This may reduce flier-projectiles, i.e., one or more projectiles having an altered trajectory relative to an average trajectory of the other projectiles. In some examples, weighted distal intersection 654 may have sufficient mass to travel down range as a projectile and contact a target.

In other examples, body 614 and cap 616 may remain substantially consolidated until impact with a rigid object, which then causes frangible cap 616 to fracture.

FIGS. 7A through 7J are conceptual diagrams illustrating an example ammunition cartridge having a sleeve releasably coupled to a cap. Cartridge 700 may be the same as or substantially similar to cartridge 200, 300, 400, 500, and/or 600 discussed above, except for the differences described herein. For example, cartridge 700 is centered about a longitudinal axis, extends from a proximal end to a distal end, and may be coupled to a case having a propellant charge, and a payload 712 having a body 714 and a cap 716 defining a projectile cavity 717 housing one or more projectiles 718, as well as a sleeve 720 coaxial with a portion body 714 and releasably coupled to cap 716. Sleeve 720 defines an obturating ring or a driving band 721. The proximal portion of body 714 defines a skirt 742.

Cap 716 may be separately formed and coupled to sleeve 720, in the same or a substantially similar manner as discussed above in reference to body 514 and cap 516. A proximal sleeve portion 723 of sleeve 720 may interface with a recess 715 defined by body 714. For example, sleeve portion 723 may interface in a sliding engagement with recess 715. When sleeve 720 is engaged with cap 716, the interface of sleeve portion 723 and recess 715 may prevent movement of cap 716 and sleeve 720 in the distal direction. Inertia of sleeve 720 when payload 712 is accelerated in response to a pressure produced by a propellant may cause the sleeve 720 to axially translate, disengaging from cap 716. Additionally, friction between obturating ring or driving band 721 during discharge of payload 712 may urge sleeve 720 proximally relative to cap 716 and body 714 to disengage cap 716 from sleeve 720.

In some examples, body 714 may include an optional thrust bearing 713. Thrust bearing 713 may rotationally isolate the proximal portion of body 714 defining skirt 742 from the distal portion of body 714 defining projectile cavity 717. In some examples, rotational isolation of projectile cavity 717 from skirt 742 may enable skirt 742 to engage a rifling of a barrel while transferring a reduced torque or no torque to projectile cavity 717 and/or projectiles 718.

FIGS. 7G through 7J illustrate separation of cap 716 from sleeve 720 to facilitate release of projectiles 718 when discharged from a firearm 790. Pressure (indicated by arrow P) of propellant gases accelerates payload 712 (FIG. 7G). When travelling through a rifled barrel of firearm 690, the rifling may cause the payload to spin in a clockwise direction (indicated by arrow S). In some examples, skirt 742 that may be urged by pressure P radially outward to enhance sealing of propellant gases, engage rifling to cause rotation of body 714, or both.

An inertia (indicated as arrow I) of sleeve 720 and/or a friction between a portion of sleeve 720 (e.g., obturating ring or driving band 721) causes sleeve 720 to disengage from cap 716 (FIG. 7H).

Upon breeching the muzzle, payload 712 may experience an air-resistance (indicated by arrow A), a centripetal force (indicated by arrow C), or both (FIG. 7I). Additionally, a muzzle blast produced by the propellant gas may cause skirt 742 to flare radially outward.

Continued air-resistance with skirt 742 may slow body 714 and sleeve 720 while maintaining a trajectory better than a body without a skirt (FIG. 7J). Projectiles 718 may continue down range as body 714 slows, without a portion of body 714 altering the trajectory of individual projectiles. This may reduce flier-projectiles. Cap 716 may fall away or have sufficient mass to travel down range as a projectile and contact a target. Alternatively, cap 716 may include a frangible material that is fractured and falls away from projectiles 718, as discussed above.

FIGS. 8A through 8J are conceptual diagrams illustrating an example ammunition cartridge having a frangible cap with a body positioned to fracture the cap. Cartridge 800 may be the same as or substantially similar to cartridge 200, 300, 400, 500, 600, and/or 700 discussed above, except for the differences described herein. For example, cartridge 800 is centered about a longitudinal axis, extends from a proximal end to a distal end, and may be coupled to a case having a propellant charge, and a payload 812 having a body 814 and a cap 816 defining a projectile cavity 817 housing one or more projectiles 818, as well as a sleeve 820 coaxial with a portion body 814 and releasably coupled to cap 816. Sleeve 820 defines an obturating ring or a driving band 821. The proximal portion of body 814 defines a skirt 842.

Cap 816 is integrally formed with sleeve 820, defining a skive 825. Skive 825 is configured to, in response to a predetermined force, fracture to at least partially separate cap 816 from sleeve 820. Forming cap 816 and sleeve 820 as an integral component may improve manufacturability, sealing of projectile cavity from debris intrusion, or both compared to cartridges having a separately formed cap and sleeve.

A proximal sleeve portion 823 of sleeve 820 may interface with a recess 815 defined by body 814 in the same or substantially similar manner as described above in reference to sleeve 720 and body 714.

FIGS. 8G through 8J illustrate separation of cap 816 from sleeve 820 to facilitate release of projectiles 818 when discharged from a firearm 890. Pressure (indicated by arrow P) of propellant gases accelerates payload 812 (FIG. 8G). When travelling through a rifled barrel of firearm 890, the rifling may cause the payload to spin in a clockwise direction (indicated by arrow S). In some examples, skirt 842 that may be urged by pressure P radially outward to enhance sealing of propellant gases, engage rifling to cause rotation of body 814, or both.

An inertia (indicated as arrow I) of sleeve 820 and/or a friction between a portion of sleeve 820 (e.g., obturating ring or driving band 821) causes skive 825 to fracture and sleeve 820 to disengage from cap 816 (FIG. 8H).

Upon breeching the muzzle, payload 812 may experience an air-resistance (indicated by arrow A), a centripetal force (indicated by arrow C), or both (FIG. 8I). Additionally, a muzzle blast produced by the propellant gas may cause skirt 842 to flare radially outward.

Continued air-resistance with skirt 842 may slow body 814 and sleeve 820 while maintaining a trajectory better than a body without a skirt (FIG. 8J). Projectiles 818 may continue down range as body 814 slows, without a portion of body 814 altering the trajectory of individual projectiles. This may reduce flier-projectiles. Cap 816 may fall away or have sufficient mass to travel down range as a projectile and contact a target. Alternatively, cap 816 may include a frangible material that is fractured and falls away from projectiles 818, as discussed above.

FIGS. 9A through 9I are conceptual diagrams illustrating an example ammunition cartridge having a body with a burst hole to fracture a frangible cap. Cartridge 900 may be the same as or substantially similar to cartridge 200, 300, 400, 500, 600, 700, and/or 800 discussed above, except for the differences described herein. For example, cartridge 900 is centered about a longitudinal axis, extends from a proximal end to a distal end, and may be coupled to a case having a propellant charge, and a payload 912 having a body 914 and a cap 916 defining a projectile cavity 917 housing one or more projectiles 918. The proximal portion of body 914 defines a skirt 942.

Cap 916 may be separately formed and coupled to body 914, in the same or a substantially similar manner as discussed above in reference to body 514 and cap 516. Cap 916 includes a frangible material and, optionally, may include skives configured to facilitate fracture of cap 916 in response to a selected force.

Body 914 defines at least one aperture 913 configured to, when discharged from a firearm, in response to a propellant gas produced by a propellant, pass therethrough a portion of the propellant gas from a propellant cavity to projectile cavity 917. In this way, projectile cavity 917 may be at least partially pressurized during discharge to produce a desired effect on body 914, cap 916, or both. In some examples, aperture 913 may include a valve configured to close in response to a threshold pressure. For example, the threshold pressure may be 10,000 pounds per square inch (psi), 20,000 psi, or 30,000 psi. The threshold pressure may be selected based on the desired effect on body 914 or cap 916, such as a pressure required to fracture at least a portion of cap 916.

In some examples, an elongate tube 911 may be fluidly coupled to the aperture. The elongate tube may extend from a proximal end fluidly coupled to aperture 913 to a distal end disposed adjacent to cap 916. When discharged from a firearm, in response to a propellant gas produced by the propellant, aperture 913 and elongate tube 911 may pass therethrough a portion of the propellant gas to rupture or displace relative to body 914 at least a portion of cap 916.

FIGS. 9G through 9I illustrate fracture of cap 916 from pressurization of projectile cavity 917. During discharge, separation of body 914 and cap 916 from projectiles 918 when may be similar to or substantially the same as described above with reference to cartridges 500 and/or 600.

When propellant gases begin to accelerate payload 912, the pressure (indicated as arrow P) may urge at least a portion of the propellant gases into projectile cavity 917 (FIG. 9G). As pressure increases in projectile cavity 917, cap 916 may at least partially fracture (FIG. 9H). For example, cap 916 may fracture at one or more skives or portions of cap 916 where pressure may concentrate, such as a distal end of an elongate tube (elongate tube 911). As pressure continues to increase, or in response to an air-resistance as described above, cap 916 may continue to fracture to fully expose projectiles 918 (FIG. 9I).

FIGS. 10A through 10D are conceptual diagrams illustrating an example projectile retainer 1000 of an ammunition cartridge. In some examples, to secure and facilitate patterning of projectiles 1018, a payload of a cartridge may include retainers 1000. For example, any of cartridge 200, 300, 400, 500, 600, 700, 800, and/or 900 may include one or more projectile retainers 1000.

Projectile retainer 1000 may be disposed within a projectile cavity and configured to retain projectiles 1018 in a selected special arrangement. For example, retainer 1000 extends from a distal end 1004 to a proximal end 1006. Each of distal end 1004 and proximal end 1006 may include chamfered or curved surfaces corresponding to a curvature of an interior of a projectile cavity (e.g., a curvature of a cap or a curvature of a distal facing surface of a proximal cup, i.e., a shot cup). Retainer 1000 includes baffles 1008 defining four quadrants 1010, each quadrant 1010 sized to receive a column of projectiles 1018. In some examples, adjacent projectiles of a column may be separated by additional radially and circumferentially extending baffles. Retainer 1000 may be formed using any suitable method, which may include injection molding, heat forming, or overmolding at least a portion of retainer around projectiles.

As illustrated in FIG. 10B, baffles 1008 may include a plurality of recesses 1012 that are configured to receive therein at least a portion of a respective projectile 1018. The recesses 1012 of adjacent baffles are configured to receive in a friction fit, a respective projectile. In this way, projectiles 1018 may be loaded into and secured with retainer 1000. This may facilitate manufacture. Additionally, or alternatively, when discharged from a firearm, the friction-fit retainment may resist radially outward motion of projectiles (e.g., radial acceleration due to centripetal force). In this way, retainer 1000 may provide a smaller patterning of projectiles 1018 compared to a cartridge that does not include retainer 1000.

In some examples, baffles may be configured to more securely retain projectiles. For example, as illustrated in FIG. 10D, retainer 1000B includes baffles 1004B and surrounds a majority of a circumferential diameter of projectiles 1018B.

Although illustrated as including baffles, in other examples, retainer 1000 may include wire cages, adjacently coupled cups, other projectile retainment features, or combinations thereof. For example, a retainer may include a cage having at least one axial extending support, at least one radially extending support, and/or at least one circumferentially extending support. An axial extending support may be configured to constrain projectiles 218 in at least one of a circumferential direction and a radial direction. A radially extending support may be configured to constrain projectiles in at least one of a circumferential direction and an axial direction. A circumferentially extending support may be configured to constrain the one or more projectiles in at least one of a radial direction and an axial direction.

Additionally, or alternatively, after projectiles and an optional retainer are loaded into a projectile cavity or body, a resin, a gel, or another fluid may be introduced to at least a portion of fill void space in the projectile cavity. In some examples, the fluid may harden, e.g., a liquid resin may harden. Filling the void space with a fluid may further retain projectiles and improve resistance to environmental factors during storage or use.

Additionally, or alternatively, two or more projectiles may be coupled via a wire or similar elongate member to control a spread between adjacent projectiles. In some examples, all of the projectiles may be connected by a web of wire or the like.

FIGS. 11A through 11F are conceptual diagrams illustrating an example ammunition cartridge 1100 having a body 1150 with crushable portion 1152. Cartridge 1100 may be the same as or substantially similar to cartridge 200, 300, 400, 500, 600, 700, 800, and/or 900 discussed above, except for the differences described herein. For example, cartridge 1100 is centered about a longitudinal axis, extends from a proximal end to a distal end, and may be coupled to a case having a propellant charge, and a payload 1112 having a first (external) body 1114 and a cap 1116 defining a projectile cavity 1117 housing one or more projectiles 1118. The proximal portion of body 1114 defines a skirt 1142. Cartridge 1100 includes a second (internal) body 1150 having a crushable portion 1152. Crushable portion 1152 is configured to, when payload is accelerated by pressure produced by a propellant, in response to an inertia of payload 1112 (e.g., projectiles 1118), deform, compress, or otherwise crush to disengage second body 1150 from cap 1116.

Crushable portion 1152 includes one or more discs 1156 extending in the radial-circumferential plane and one or more pillars 1154 extending in the axial plane and positioned between adjacent discs 1156. Respective discs 1156 may include a shot cup and a propellant cup. In some examples, one or more intermediate discs may be disposed between the to shot cup and the propellant cup.

As illustrated in FIGS. 11C and 11D, in response to a pressure (indicated by arrow P) produced by a propellant, an inertia of projectiles 1118 (indicated by arrows I) may produce a force on shot cup disc 1156. This force may be transferred to pillars 1154. The force may increase until pillars 1154 yield or otherwise collapse. When pillars 1154 collapse, second body 1150 may disengage from cap 1116.

Other configurations of crushable portion 1152 are illustrated in FIGS. 11E and 11F. For example, crushable portion 1152E may include a bellows and crushable portion 1152F may include a cross brace.

FIGS. 12A through 12F are conceptual diagrams illustrating an example ammunition cartridge 1200 having a polymer front hinge 1270. Cartridge 1200 may be the same as or substantially similar to cartridge 200, 300, 400, 500, 600, 700, 800, 900, and/or 1100 discussed above, except for the differences described herein. For example, cartridge 1200 is centered about a longitudinal axis, extends from a proximal end to a distal end, and may be coupled to a case having a propellant charge, and a payload 1212 having a body 1214 and a cap 1216 defining a projectile cavity 1217 housing one or more projectiles 1218, as well as a sleeve 1220 coaxial with a portion body 1214 and releasably coupled to cap 1216. Sleeve 1220 defines an obturating ring or a driving band 1221. The proximal portion of body 1214 defines a skirt 1242.

Cap 1216 is integrally formed with sleeve 1220 and may define a skive 1225, as discussed above in reference to cartridge 800. For example, a proximal sleeve portion 1223 of sleeve 1220 may interface with a recess 1215 defined by body 1214. Unlike cartridge 800, body 1214 may define distal fins 1280. Cap 1216 is configured to encapsulate fins 1280 in a deformed configuration. When in an undeformed configuration, fins 1280 may extend in an axial plane or radially outward.

FIGS. 12C through 12F illustrate separation of cap 1216 from sleeve 1220 to facilitate deployment of fins 1280 and release of projectiles 1218 when discharged from a firearm 1290. Pressure (indicated by arrow P) of propellant gases accelerates payload 1212 (FIG. 12C). When travelling through a rifled barrel of firearm 1290, the rifling may cause the payload to spin in a clockwise direction (indicated by arrow S). In some examples, skirt 1242 that may be urged by pressure P radially outward to enhance sealing of propellant gases, engage rifling to cause rotation of body 1214, or both.

An inertia (indicated as arrow I) of sleeve 1220 and/or a friction between a portion of sleeve 1220 (e.g., obturating ring or driving band 1221) causes skive 1225 to fracture and sleeve 1220 to disengage from cap 1216 (FIG. 12D).

Upon breeching the muzzle, payload 1212 may experience an air-resistance (indicated by arrow A), a centripetal force (indicated by arrow C), or both and fins 1280 may deploy (FIG. 12E). Additionally, a muzzle blast produced by the propellant gas may cause skirt 1242 to flare radially outward.

Continued air-resistance with skirt 1242 and/or fins 1280 may slow body 1214 and sleeve 1220 while maintaining a trajectory better than a body without a skirt and/or fins (FIG. 12F). Projectiles 1218 may continue down range as body 1214 slows, without a portion of body 1214 altering the trajectory of individual projectiles. This may reduce flier-projectiles. Cap 1216 may fall away or have sufficient mass to travel down range as a projectile and contact a target. Alternatively, cap 1216 may include a frangible material that is fractured and falls away from projectiles 1218, as discussed above.

FIGS. 13A and 13B are conceptual diagrams illustrating an example counter-rotation muzzle device 1392. As illustrated in FIG. 13A, a rifled barrel 1390 may cause a payload 1312 to spin in a clockwise direction (indicated by arrow S). As illustrated in FIG. 13B, counter-rotation muzzle device 1392 may include rifling that is opposite that of rifled barrel 1390. Counter-rotation muzzle device 1392 may reduce the rotational rate of payload 1312, stop the rotational rate of payload 1312, or cause payload 1312 to rotate in a counterclockwise direction (as indicated by arrow R).

The cartridges descried herein may include additional or alternative features such as those described in for example U.S. Pat. Nos. 10,422,611; 9,879,957; 9,360,223; 9,360,223; 6,260,484; 7,607,393; 9,046,332; 7,765,933; 10, 466,022; 10,222,187; 10,041,773; 10,001,355; 10,551,154; 10,520,288; 9,863,746; 9,651,346; 9,273,941; 9,157,713; 9,733,052; 9,329,009; 9,360,284; 6,805,057; 6,244,187; 6,530,328; 6,305,292; 6,178,890; 7,225,741; 7,621,208; 7,984,668; 8,783,152; 7,278,358; 8,146,505; 8,539,885; 8,485,102; 9,494,397; 10,436,560; 9,470,492; 9,835,426; 10,088,287; U.S. Design patent application No. D847,294; D847,293; D810,226; D809,622; D849,569; D884821; D813,974; D689,975; D724,690; the entirety of each of which is incorporated herein by reference.

The following clauses illustrate example subject matter described herein:

• • Clause 1. An ammunition cartridge 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.
  • Clause 2. The cartridge of clause 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.
  • Clause 3. The cartridge of clause 1 or 2, 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).
  • Clause 4. The cartridge of any one of clauses 1 through 3, wherein cartridge further comprises at least one of an obturating ring and a driving band.
  • Clause 5. The cartridge of clause 4, wherein the at least one of the obturating ring and the driving band is rotatably coupled to the body sidewall and, when discharged from a firearm, is configured to engage a rifling of the firearm and decouple a spin rate of the body relative to the rifling.
  • Clause 6. The cartridge of clause 4 or 5, wherein the at least one of the obturating ring and the driving band is integrally formed with the body sidewall.
  • Clause 7. The cartridge of any one of clauses 4 through 6, wherein the at least one of the obturating ring and the driving band is disposed radially adjacent at least a first portion of the cap, wherein, when discharged from a firearm, the 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.
  • Clause 8. The cartridge of any one of clauses 1 through 7, 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.
  • Clause 9. The cartridge of clause 8, wherein, when discharged from a firearm, in response to an axial force on the body, the sleeve is configured to translate axial in the proximal direction relative to the cap to disengage from the proximal cap portion.
  • Clause 10. The cartridge of clause 8 or 9, wherein the at least one of the obturating ring and the driving band integrally formed with or coupled to the sleeve.
  • Clause 11. The cartridge of any one of clauses 1 through 10, 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.
  • Clause 12. The cartridge of any one of clauses 1 through 11, wherein the proximal cup defines a proximal facing surface configured to, when discharged from a firearm, in response to a pressure produced by the propellant charge, splay in a radial direction to seal propellant gases proximal of the body.
  • Clause 13. The cartridge of any one of clauses 1 through 12, wherein the proximal cup comprises a proximally extending skirt configured to, when discharged from a firearm, splay in the radial direction.
  • Clause 14. The cartridge of clause 13, wherein the skirt extends from a plane normal to the longitudinal axis and extending through a proximal end of the projectile cavity to a proximal edge a length within a range from about 0.750 inches (1.91 centimeters (cm)) to about 0.800 inches (20.32 cm).
  • Clause 15. The cartridge of clause 13 or 14, wherein the skirt is configured to engage a rifled barrel of a firearm to cause a first spin of the body in a first circumferential direction.
  • Clause 16. The cartridge of any one of clauses 13 through 15, wherein the skirt is configured to engage a counter-rotating muzzle device of a firearm to at least one of partially despin of the body or cause a second spin of the body in a second, opposing circumferential direction, wherein a bore of the counter-rotating muzzle is greater than a bore of the rifled barrel.
  • Clause 17. The cartridge of any one of clauses 1 through 16, 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, urge at least a portion of the body sidewall radially outward.
  • Clause 18. The cartridge of any one of clauses 1 through 17, wherein the proximal cup defines an aperture configured to, when discharged from a firearm, in response to a propellant gas produced by the propellant, pass therethrough a portion of the propellant gas.
  • Clause 19. The cartridge of clause 18, wherein the aperture comprises a valve configured to close in response to a threshold pressure.
  • Clause 20. The cartridge of clause 18 or 19, further comprising an elongate tube extending from a proximal end fluidly coupled to the aperture to a distal end disposed adjacent to the cap, wherein the elongate tube is configured to, when discharged from a firearm, in response to a propellant gas produced by the propellant, pass therethrough a portion of the propellant gas to rupture or displace relative to the body at least a portion of the cap.
  • Clause 21. The cartridge of any one of clauses 1 through 15, wherein the cap comprises a frangible material configured to, when discharged from a firearm, fracture to expose the one or more projectiles.
  • Clause 22. The cartridge of clause 21, wherein the frangible material defines at least part of the proximal cap portion.
  • Clause 23. The cartridge of any one of clauses 1 through 22, 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.
  • Clause 24. The cartridge of any one of clauses 1 through 23, 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.
  • Clause 25. The cartridge of any one of clauses 1 through 24, wherein the at least one projectile comprises a plurality of projectiles configured to, when discharged by the propellant from a rifled barrel of a firearm, at a distance within a range from about 30 meters to about 40 meters, orient in a pattern having maximum distance between two projectiles of the plurality of projectiles of less than about 1 meter or less than 0.5 meters.
  • Clause 26. The cartridge of any one of clauses 1 through 25, wherein the at least one projectile comprises pellets having diameter within a range from about 0.24 inches (6.10 mm) to about 0.36 inches (9.14 mm).
  • Clause 27. The cartridge of any one of clauses 1 through 26, wherein the at least one projectile comprises at least one of an iron alloy, a titanium alloy, or lead.
  • Clause 28. The cartridge of any one of clauses 1 through 27, further comprising one or more projectile retainers disposed within the projectile cavity and configured to retain the one or more projectiles in a selected special arrangement.
  • Clause 29. The cartridge of clause 28, wherein the one or more projectile retainers comprise a cage comprising at least one axial extending support and at least one radially extending support, wherein the at least one axial extending support is configured to constrain the one or more projectiles in at least one of a circumferential direction and a radial direction, and wherein the at least one radially extending support is configured to constrain the one or more projectiles in at least one of a circumferential direction and an axial direction.
  • Clause 30. The cartridge of clause 29, wherein the cage further comprises at least one circumferentially extending support, and wherein the at least one circumferentially extending support is configured to constrain the one or more projectiles in at least one of a radial direction and an axial direction.

While the disclosure has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the disclosure is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore, it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the disclosure, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary.