Abstract: A modular firearm is disclosed. The firearm that can be configured to operate using ammunition of different calibers via interchangeability of only a few parts. The firearm includes a foldable butt stock assembly for quickly and easily converting the firearm from an extended operating configuration to a compact transport configuration, and vice-versa. Additionally, the firearm includes a modular hand guard assembly having multiple mounting platforms for accommodating a variety of different accessories.

Abstract: A quick-detach barrel mounting system for removing and attaching a barrel to a receiver of a firearm. The quick-detach barrel mounting system can include a barrel nut having a body defining an axial bore. A proximal end of the barrel is received at least partially through the axial bore, and the barrel nut releasably engages a front end of the receiver. A hand guard can be mounted to the receiver and can define a cutout proximate the receiver. The hand guard at least partially encloses at least a portion of the barrel and the barrel nut, and the cutout is at least partially aligned with the barrel nut. At least a portion of the barrel nut is accessible via the cutout of the hand guard for at least partially disengaging and engaging the barrel nut with the receiver when the hand guard is mounted on the receiver.

Abstract: A gas cutoff system for use with a gas-operated firearm. The gas cutoff system includes a gas block affixed to the barrel and having a plurality of openings adjacent the barrel for receiving gas redirected from the barrel of the firearm upon firing. At least one gas cylinder is disposed within the gas block and includes a piston disposed within and moveable along the gas cylinder. A valve assembly is disposed within the gas cylinder adjacent to the at least one piston. The valve assembly includes a selectively closeable valve that can be actuated upon firing of the firearm when the volume/pressure of gas entering the gas block through the plurality of openings overcomes a biasing force of a spring so as to actuate movement of the valve within the gas cylinder. A portion of the valve is moved to a location blocking the openings through which the gas is entering the gas block to prevent excess gas from entering the gas operating system.

Abstract: A three component bullet with a core retention feature and a method of forming the bullet is described. The bullet can include a jacket surrounding a core and a locking band disposed around a circumference of the jacket and the core. The locking band can be received in a circumferential depression formed in the jacket and the core such as by compressing the core to cause the core and the jacket to expand radially fore and aft of the locking band. The circumferential depression can include shoulders that are in compressive engagement with the locking band to help secure the locking band in place. The circumferential depression can include an inwardly-extending annular band of jacket material which embeds itself into the core material with the result that the core is locked inside the jacket.

Abstract: A low-cost, reduced friction expanding bullet with an improved core retention feature and a method of manufacturing the bullet is described wherein a cylindrical jacket containing a compacted malleable metal core having an open end and a closed end is forced into a forming die having a bottleneck shaped interior resulting in a bottleneck shaped pre-form wherein the outside diameter of the open-ended forward portion of the jacket is smaller than the outside diameter of its closed rearward portion and wherein a transition shoulder separates the two diameters. The pre-form is then placed in a profile die wherein a base punch exerts an axial force against said pre-form which axially collapses a portion of the jacket wall forward of the transition shoulder subsequently forcing said portion of the jacket wall radially inwardly providing a reduction in bearing surface and forming an internal core-locking radius while at the same time forming an ogival bullet nose.

Abstract: A gas operating system for a firearm renders the firearm capable of firing a wide range of shot loads by passively or automatically compensating for different shot loads. The firearm includes a plurality of ports formed in the firearm barrel, and corresponding ports formed in a gas block of the gas operating system. The ports tap gases generated during firing which are used to cycle the firearm. When firing different cartridge loads, differing combinations of the ports are selectively at least partially blocked or otherwise obstructed by the cartridge casing according to the size of the cartridge. Additionally, the gas operating system includes compensating gas pistons with internal relief valves that can bleed off excess gas to compensate for larger shot loads regardless of the size of the cartridge.

Abstract: An extraction system for extracting a cartridge from a firing chamber of a firearm includes an extractor mounted within the firearm bolt which has a bolt head with a plurality of lugs proximate a bolt face, a cartridge recess extending axially inward from the bolt face, and an extractor aperture extending radially outward through one of the lugs. A spring aperture extends axially through the one lug and intersects with the extractor aperture. The extractor is slidably mounted within the extractor aperture and has a hook portion for coupling with the cartridge and a transverse spring bore extending through a mid-section of the extractor. The extraction system further includes an extractor spring having an anchor portion mounted about the outer surface of the bolt and a cantilever spring portion inserted through the spring aperture and into the transverse hole in the extractor, for resiliently biasing the extractor toward the cartridge recess.

Abstract: A pistol thumb safety that is capable of being coupled to a frame of a pistol, the thumb safety including a safety body adapted to be movably mounted to the frame so that the body is movable between firing and safe positions. The safety body includes an outer side surface, an inner side surface, and a top portion. A blocking feature is formed along the top portion of the safety body, wherein the blocking portion engages the slide of the pistol when the safety body is in its safe position. As a result, the slide is movable along the safety body for clearing the chamber of the pistol while the safety body is maintained in its safe position.

Abstract: A projectile is provided with a projectile tip having enhanced aerodynamic properties to improve accuracy of the projectile. The tip has a body having a base or lower end, an upper end and a curved, side wall between its upper and lower ends that defines an ogive tip length. The tip is received with a projectile jacket and also can have a series of aerodynamic features formed in its body to modify air flow about the body of the projectile in flight.

Abstract: A gas system for an autoloading firearm wherein the gas used to cycle the weapon can be restricted automatically through a mechanical shutoff actuated by the installation of a suppressor on the weapon. The gas system could be used to actuate either a piston to mechanically operate the weapon or a gas impingement mechanism wherein the gas is redirected into the bolt carrier assembly to directly actuate the unlocking and cycling of the bolt and bolt carrier group. A gas block for the firearm includes a spring-loaded plunger assembly positioned within a bore of the gas block and oriented parallel to a bore of a barrel of the firearm, the plunger assembly including a regulator plunger, a regulator bushing, a regulator spring, and a regulator cap. Mounting a suppressor over the muzzle depresses the regulator plunger driving it rearward, the rearward movement of the regulator plunger blocking one of gas ports in the gas block to automatically reduce the volume of propellant gases directed into the gas system.