Abstract: An automatic action assembly of a firearm, comprising a barrel (2) with a sliding cartridge chamber (1) arranged in a sliding way between the front and rear dead center. The movement of the sliding chamber (1) is delimited by at least one first stop (3) on the sliding chamber (1) and a corresponding at least one second stop (4) connected to the barrel (2). Between the first stop (3) and second stop (4), there is a play (A). In the rear part of the sliding chamber (1), a breech block (5) is lockably connected at the end of which a breech block (5) carrier (6) is to mounted in a sliding way. The breech block (5) carrier (6) is pushed by a return spring (7) towards the barrel (2). The breech block (5) is fitted with an unlocking mechanism for delayed disconnection of the breech block (5) from the sliding chamber (1).

Abstract: A fixed-barrel, gas-operated firearm having its barrel concentrically mounted within a pressure tube enclosing substantially all of the moving parts of the firearm's action. A gas cup reciprocates under the influence of propellant gas pressure when the firearm is fired, driving slide members that link the pressure cup to the firearm's bolt rearward within the pressure tube, unlocking the breech, rotating and retracting the bolt, discharging the spent cartridge casing and then advancing the bolt to chamber a new cartridge.

Abstract: A fixed-barrel, gas-operated firearm having its barrel concentrically mounted within a pressure tube enclosing substantially all of the moving parts of the firearm's action. A gas cup reciprocates under the influence of propellant gas pressure when the firearm is fired, driving slide members that link the pressure cup to the firearm's bolt rearward within the pressure tube, unlocking the breech, rotating and retracting the bolt, discharging the spent cartridge casing and then advancing the bolt to chamber a new cartridge.

Abstract: An automatic firearm that includes a unitary portion including a human interface and a barrel defining a longitudinal dimension. A slidable portion is attached to the unitary portion so as to permit the slidable portion to slide in the longitudinal dimension. The slidable portion includes at least a portion of a firing chamber. In addition, a lock is adapted to selectably fix the slidable portion relative to the unitary portion. Also, a chamber attached to the unitary portion and an inertial member permitted to move inside the chamber and urged into a first position, the inertial member adapted to translate into a second position, displaced from said first position by at least 0.1 cm, upon firing of the firearm, in which second position the inertial member begins to change the position of the lock, thereby permitting the moveable portion to move relative to the unitary portion.

Abstract: A bolt head locking arrangement for a recoil operated weapon where projectile is expelled by discharging a cartridge. The weapon comprising an action body, a barrel, and a bolt assembly, the bolt assembly being slidable within the action body. The bolt assembly comprising a bolt head, a locking slide and a firing pin, and a locking means arranged so that, upon loading a new cartridge for discharging, the locking means positively lock the bolt head such that, for a predetermined amount of time after the loaded cartridge is discharged, the locked bolt head stops the cartridge from retreating into the action body. The locking means is substantially in an in-line configuration with the bolt assembly.

Abstract: A bolt locking assembly for a weapon simulator, the weapon simulator having a bolt affixed to a firearm housing providing recoil to the user. The bolt is connected to a piston housed in a piston chamber inside the housing. A gas supply provides a compressed gas or fluid into the piston chamber to generate movement and recoil of the piston. After the weapon simulator has been fired a predetermined number of times, the bolt locking assembly will obstruct operation of the bolt and piston. The bolt locking assembly includes a lock actuator port engaging the piston chamber, a locking apparatus positioned within the housing proximate the bolt, and a lock channel between said lock actuator port and said locking arm, wherein the lock channel directs gas to said locking apparatus to actuate said locking apparatus and fix the bolt in place.

Abstract: A blow-back operating automatic firearm has a sliding mass carried with its bolt carrier assembly to increase the dwell time of the bolt at the breech when the bolt is in battery position for firing. The sliding mass reduces the tendency of the bolt to bounce-off the head end of the seated cartridge, thereby reducing the risk that a misfiring will occur.

Abstract: A barrel for an automatic firearm which cycles on recoil action is provided with a transverse pin extending across the top of the rearward portion of the chamber. This pin nests within the extraction groove of a cartridge sing during firing. On cycling, the transverse pin deflects the spent case downwardly towards an ejector which effects ejection of the casing.

Abstract: A light-weight, shoulder-firable, armor-penetrating gun characterized by a recoiling barrel confined to coaxial movement by a pair of longitudinally spaced bushings within the gun housing, the recoiling barrel being adapted to carry rearward the elongated bolt carrier containing the bolt for compressing the recoil spring, and a stop mechanism associated with the barrel and the housing for limiting the rearward travel of the barrel for early disengagement between the barrel and the bolt carrier, and a barrel spring in the front of the housing for returning the barrel to its normal battery position.

Abstract: A bolt assembly for an automatic firearm which operates using kinetic recoil energy that includes a floating bolt element, a rotatable locking bolt head and a return spring interposed between them, all in communication with the barrel. The bolt head is formed with a cylindrical portion having two crescent shaped projections located at diametrically opposite points along the circumference of the cylindrical portion. The barrel is formed with two diametrically opposite recesses associated with and shaped to correspond to the projections. The barrel is also formed with a pair of grooves, each groove associated with a recess such that the projections may enter and exit the grooves through the recesses. The grooves are staggered with respect to the recesses and have an angular extension such that the projections may enter and be retained within the grooves.

Abstract: A device for loading and firing semi-automatic arms, particularly pistols, and comprising a plurality of follower lugs or pins carried in the slide, and a corresponding plurality of inclined grooves carried in the yoke and engaged by the lugs or pins so as to disengage the yoke and the bolt from the barrel when the slide is retracted under the pressure of the gases from a fired cartridge.