Abstract: Disclosed is a firearm barrel that includes a bore, a rifling pattern along a length of the bore, and a grooved gas-venting pattern along a length of the bore that exceeds an envelope of the rifling pattern. The rifling pattern imparts spin on a bullet to stabilize the bullet in flight, while the grooved gas-venting pattern allows expanding propellant gases to escape around the bullet as it travels down the bore, causing a reduction in internal pressure acting on the bullet and reducing bullet velocity. The inventive barrel can reduce bullet velocity of standard ammunition, such as 5.56×45 mm NATO or 7.62×51 mm NATO to a subsonic velocity, or approximately 1125 feet per second at sea level without the need for specialized ammunition.

Abstract: Provided is a blank firing adapter for a firearm that prevents a bullet or fragmentation from exiting a firearm barrel and traveling downrange. The device includes a body, a fore end, an aft end, a bore, a transverse exhaust hole, and a flange. The body is positioned within a muzzle end of the firearm barrel. The fore end includes a solid material to prevent bullet fragmentation from directly exiting the barrel in a direction coinciding with a point-of-aim direction when a live round is fired, and the transverse exhaust hole redirects gas traveling through the bore to a direction transverse to the muzzle end of the barrel. The device generates backpressure to permit automatic cycling of a weapon system, safely catches a fired bullet without any fragmentation to travel downrange, and is visually inconspicuous to the casual observer when installed, while allowing for the use of externally attached devices.

Abstract: Provided is a firearm cartridge chamber with a relief feature that traps a portion of a cartridge case within the cartridge chamber when fired. The relief feature causes the cartridge case to deform within the chamber, wherein it optionally separates into a forward section and a rearward section. The deformed case remains trapped after firing, preventing extraction of the fired case and the chambering or firing of any subsequent cartridges, thereby causing a firearm malfunction. The cartridge chamber can distinguish between higher and lower pressure cartridges by allowing for normal firing and function with blank training ammunition while also facilitating localized deformation of the cartridge case when firing standard ammunition that includes one or more projectiles. The inventive chamber prevents more than one higher pressure round from firing while allowing lower pressure or training rounds to fire without limitation, which aids in enhanced safety during training exercises.

Abstract: Provided is a firearm cartridge chamber with a relief feature that traps a portion of a cartridge case within the cartridge chamber when fired. The relief feature causes the cartridge case to deform within the chamber, wherein it optionally separates into a forward section and a rearward section. The deformed case remains trapped after firing, preventing extraction of the fired case and the chambering or firing of any subsequent cartridges, thereby causing a firearm malfunction. The cartridge chamber can distinguish between higher and lower pressure cartridges by allowing for normal firing and function with blank training ammunition while also facilitating localized deformation of the cartridge case when firing standard ammunition that includes one or more projectiles. The inventive chamber prevents more than one higher pressure round from firing while allowing lower pressure or training rounds to fire without limitation, which aids in enhanced safety during training exercises.

Abstract: A cartridge case with a case crush region that facilitates an additional amount of case crush in the axial direction, per unit of input force and energy, as compared to an identical cartridge case without such a region. The crush region may conceivably be either of a fully or partially circumferential nature with applicability to any style cartridge case, be it bottleneck or straight-walled and of any rim configuration (rimmed, semi-rimmed, rimless, rebated-rim, belted) and without prejudice to the case material (brass, stainless steel, polymer, etc.). This feature may be incorporated into the design of existing cartridge cases as well as future designs.

Abstract: A bottleneck cartridge chamber wherein a circumferential relief recess is placed within the shoulder region of the chamber. As opposed to the continuous angled shoulder of conventional cartridge chambers, the proposed relief recess is envisioned as an angular segment of larger included angle than the conventional chamber shoulder angle (thereby creating a compound angle cartridge chamber shoulder region) or a radial recess that would eliminate a portion of the conventional chamber shoulder.

Abstract: A flash suppressor of the open prong type having a twist in its structure formed of alternating grooves and flutes or prongs provides a highly effective flash suppression for small and medium caliber weapons and especially for automatic weapons and machine guns when placed on the end of their barrels. The orientation of the direction of the twist of the structure is in a direction opposite to the direction of the rifling in its firearm barrel. Various objective laboratory tests and subjective user evaluation on its performance prove out its effectiveness in terms of mitigating visible flash on shorten machine gun barrels as well as standard full length barrels used in critical helicopter black out operations using night vision equipment. In addition, precise aiming of a weapon equipped with the inventive flash suppressor exhibits lower dispersion of actual projectile impact compared to conventional flash suppressors.

Abstract: A gun barrel adaptor includes a body having a central bore therethrough and including a flange, the flange having a hole therethrough, the body having a lower side on one side of the flange and an upper side on another side of the flange; a flat spring attached to a lower side of the flange; a stop disposed in the hole in the flange and extending above an upper side of the flange, the flat spring being operable to resist movement of the stop towards the lower side of the body; and at least one locking tab disposed on the upper side of the body. The gun barrel adaptor provides for quick change modularity of muzzle devices without the use of any special tools.