Abstract: A double stack magazine for a firearm comprises a tubular magazine body formed of polymer defining a cavity for holding a stack of cartridges, a spring, and a follower biased by the spring for dispensing cartridges from the magazine. The cartridges may be rimmed cartridges in one embodiment arranged in a vertically staggered side-to-side arrangement. Other type cartridges may be used. The magazine includes a lower double stack section and upper single stack section. A metal magazine shape retention device is coupled to the midsection of the magazine body which structurally reinforces the polymer body to prevent bulging when cartridges are loaded.

Abstract: A firearm with dual-acting safety mechanism includes a hammer, sear operable to hold the hammer in a cocked position, and trigger mechanism including a trigger and trigger bar which collectively operates to rotate the sear to release the hammer. The safety mechanism includes a safety mode selector or actuator cooperating with a secondary safety link. In one arrangement, linearly moving the selector actuates and rotates the safety link which simultaneously both blocks the hammer and displaces the trigger bar such that the sear can no longer be actuated via a trigger pull.

Abstract: A folding stock coupling system for a firearm. An openable/closeable hinge mechanism comprising front and rear hinge elements pivotably mounts the rear stock to the main body of the firearm. The hinge mechanism is selectively movable between a locked condition when the stock is unfolded and inline with the main body for firing, and an unlocked condition when the stock is folded forward and offset from the main body for compact carrying or storage. A manually movable actuating button of the hinge mechanism selectively locks or unlocks the rear to the front hinge members in the locked and unlocked conditions, respectively. Embodiments include a detent mechanism for removably retaining the folded position. An elongated rear mounting extension coupled to the rear hinge member provides a common stock mounting interface compatible for interchanging a plurality of different stocks to the firearm each sharing a common mounting profile.

Abstract: A folding stock coupling system for a firearm. An openable/closeable hinge mechanism comprising front and rear hinge elements pivotably mounts the rear stock to the main body of the firearm. The hinge mechanism is selectively movable between a locked condition when the stock is unfolded and inline with the main body for firing, and an unlocked condition when the stock is folded forward and offset from the main body for compact carrying or storage. A manually movable actuating button of the hinge mechanism selectively locks or unlocks the rear to the front hinge members in the locked and unlocked conditions, respectively. Embodiments include a detent mechanism for removably retaining the folded position. An elongated rear mounting extension coupled to the rear hinge member provides a common stock mounting interface compatible for interchanging a plurality of different stocks to the firearm each sharing a common mounting profile.

Abstract: A firearm with dual-acting safety mechanism includes a hammer, sear operable to hold the hammer in a cocked position, and trigger mechanism including a trigger and trigger bar which collectively operates to rotate the sear to release the hammer. The safety mechanism includes a safety mode selector or actuator cooperating with a secondary safety link. In one arrangement, linearly moving the selector actuates and rotates the safety link which simultaneously both blocks the hammer and displaces the trigger bar such that the sear can no longer be actuated via a trigger pull.

Abstract: A bolt assembly for firearms utilizing a blowback type operating system. The bolt assembly comprises a non-rotatable bolt slideably disposed in the receiver for forward and rearward movement and a dead blow weight assembly slideably coupled to the bolt. The dead blow weight assembly may be two-piece comprising a dead blow weight and dead blow top member. These parts are separate components movable independently of each other, but functionally interacting and cooperating under recoil after discharging the firearm to eject a spent cartridge casing and chamber a new cartridge as the action is reset. When the firearm discharged, a two-stage felt recoil force is generated by this mechanism, thereby advantageously producing peak forces which are less in magnitude than the single strong felt recoil force experienced by users with conventional one-piece bolt used in many blowback type firearms.

Abstract: A modular magazine well insert system accepts and latches different types of magazines including front and side catch styles. The system includes a plurality of magazine well inserts each having a common mounting interface which interfaces with a mounting feature formed in a receptacle of the firearm stock. The inserts may have a common basic configuration with some different features adapted for use with different magazine catch features, such as latching levers for front catch magazines or lateral apertures to access side catch magazines. A universal latch stud slideably mounted in the stock comprises features which cooperate with each of the magazine well inserts to retain and release both catch styles of magazines in the insert.

Abstract: A modular magazine well insert system accepts and latches different types of magazines including front and side catch styles. The system includes a plurality of magazine well inserts each having a common mounting interface which interfaces with a mounting feature formed in a receptacle of the firearm stock. The inserts may have a common basic configuration with some different features adapted for use with different magazine catch features, such as latching levers for front catch magazines or lateral apertures to access side catch magazines. A universal latch stud slideably mounted in the stock comprises features which cooperate with each of the magazine well inserts to retain and release both catch styles of magazines in the insert.

Abstract: A bolt assembly for firearms utilizing a blowback type operating system. The bolt assembly comprises a non-rotatable bolt slideably disposed in the receiver for forward and rearward movement and a dead blow weight assembly slideably coupled to the bolt. The dead blow weight assembly may be two-piece comprising a dead blow weight and dead blow top member. These parts are separate components movable independently of each other, but functionally interacting and cooperating under recoil after discharging the firearm to eject a spent cartridge casing and chamber a new cartridge as the action is reset. When the firearm discharged, a two-stage felt recoil force is generated by this mechanism, thereby advantageously producing peak forces which are less in magnitude than the single strong felt recoil force experienced by users with conventional one-piece bolt used in many blowback type firearms.

Abstract: A user-adjustable recoil reduction system for a firearm includes a buttstock and a butt pad assembly movably mounted to the buttstock. A spring is disposed in the buttstock which is acted on by opposing front and rear spring guides. A preload adjustment screw is rotatably coupled to the butt pad assembly which engages the rear spring guide. Rotating the screw in opposing directions alternatingly advances or retracts the rear spring guide in the buttstock. Advancing the rear spring guide compresses the spring to set a first spring preload condition and retracting the rear spring guide relaxes the spring to set a second spring preload condition different than the first condition. The spring preload conditions may be selected to match firing light or heavy type ammunition shell loads. In one embodiment, the adjustment screw is accessible for adjusting the preload without removing the butt pad assembly from the buttstock.

Abstract: A user-adjustable recoil reduction system for a firearm includes a buttstock and a butt pad assembly movably mounted to the buttstock. A spring is disposed in the buttstock which is acted on by opposing front and rear spring guides. A preload adjustment screw is rotatably coupled to the butt pad assembly which engages the rear spring guide. Rotating the screw in opposing directions alternatingly advances or retracts the rear spring guide in the buttstock. Advancing the rear spring guide compresses the spring to set a first spring preload condition and retracting the rear spring guide relaxes the spring to set a second spring preload condition different than the first condition. The spring preload conditions may be selected to match firing light or heavy type ammunition shell loads. In one embodiment, the adjustment screw is accessible for adjusting the preload without removing the butt pad assembly from the buttstock.

Abstract: A matched muzzle brake and weight system mountable on a firearm barrel is disclosed. In certain embodiments, the muzzle brake and weight are configured to have the same predetermined weight and center of gravity so that the point of aim of the firearm remains substantially unchanged when a user deploys either the muzzle brake or weight. The system permits convenient interchangeability between the muzzle brake and weight without the need for re-sighting the firearm thereby maintaining accuracy. In some embodiments, the centers of gravity of the muzzle brake and weight are located at the same position with respect to a common reference point defined by the barrel. A method for using the system is also disclosed.

Abstract: A gas operated autoloading firearm having an improved bolt carrier. The gas piston system may include a barrel defining a longitudinally-extending bullet pathway, a gas block defining a piston bore, a passageway fluidly connecting the bore with the bullet pathway for diverting combustion gas to the bore upon discharging the firearm, and a piston slidably disposed in the bore for reciprocating movement. The piston actuates a reciprocating bolt assembly including a bolt carrier slidably received in a receiver. The bolt carrier includes supporting and guiding surfaces configured to reduce receiver wear and bolt carrier drag.

Abstract: A gas operated autoloading firearm having an improved bolt carrier. The gas piston system may include a barrel defining a longitudinally-extending bullet pathway, a gas block defining a piston bore, a passageway fluidly connecting the bore with the bullet pathway for diverting combustion gas to the bore upon discharging the firearm, and a piston slidably disposed in the bore for reciprocating movement. The piston actuates a reciprocating bolt assembly including a bolt carrier slidably received in a receiver. The bolt carrier includes supporting and guiding surfaces configured to reduce receiver wear and bolt carrier drag.

Abstract: An automatic takeoff thrust management system can be used in an aircraft with at least two engines. The management system comprises an aircraft status sensor or set of sensors capable of detecting establishment of takeoff climb conditions, and engine failure detectors respectively coupled to the at least two engines and capable of detecting engine failure. The management system further comprises thrust control modules respectively coupled to the at least two engines and capable of controlling the thrust of the engines, and a controller coupled to the aircraft status sensors, the engine failure detectors, and the thrust control modules. The controller reduces thrust by a selected amount upon detecting establishment of takeoff climb conditions and, if engine failure is detected, restoring thrust to an initial or a higher schedule.