Firearms with gas piston assemblies have a receiver defining a passage receiving a reciprocating bolt assembly, a barrel defining a barrel axis and extending from the receiver in a forward direction and defining a barrel gas aperture, a gas block connected to the barrel and defining a piston bore in communication with the gas block bore, a piston assembly having a forward end operably engaged to the piston bore and a rear end operably engaged to the reciprocating bolt assembly, the piston assembly having a piston closely received in the piston bore and having a piston rear end, the piston assembly including an elongated intermediate rod having an intermediate rod forward end registered with the piston rear end and an intermediate rod rear end, and the piston assembly including a rear portion having a forward end registered with the intermediate rod rear end and a rear portion.

Firearms with gas piston assemblies have a receiver defining a passage receiving a reciprocating bolt assembly, a barrel defining a barrel axis and extending from the receiver in a forward direction and defining a barrel gas aperture, a gas block connected to the barrel and defining a piston bore in communication with the gas block bore, a piston assembly having a forward end operably engaged to the piston bore and a rear end operably engaged to the reciprocating bolt assembly, the piston assembly having a piston closely received in the piston bore and having a piston rear end, the piston assembly including an elongated intermediate rod having an intermediate rod forward end registered with the piston rear end and an intermediate rod rear end, and the piston assembly including a rear portion having a forward end registered with the intermediate rod rear end and a rear portion.

A gas block comprising a gas tube channel, a barrel channel, a gas port extending from the gas tube channel towards the barrel channel, a slot extending disposed between the gas port and the barrel channel, and an adjustment mechanism set within the slot and movably coupled to the gas block.

A gas block comprising a gas tube channel, a barrel channel, a gas port extending from the gas tube channel towards the barrel channel, a slot extending disposed between the gas port and the barrel channel, and an adjustment mechanism set within the slot and movably coupled to the gas block.

A firearm gas piston system provides tool-less removal and adjustment of gas flow along a nonlinear gradient and directs exhaust discharge away from the operator. The system includes a gas block with gas channels for directing exhaust gas away from an operator and a gas plug bore configured to accommodate insertion of a gas plug. The gas plug can include an actuator for rotating the gas plug, a key that fits within a key notch and key channel inside the gas plug bore to secure the gas plug within the bore, and a regulator portion to control the flow of discharge gas from a firearm barrel. The regulator portion includes a passage with two opening segments that accept discharge gas from the barrel and direct the gas through another opening disposed in a regulator cutout and to a piston portion of the gas block.

A firearm gas piston system provides tool-less removal and adjustment of gas flow along a nonlinear gradient and directs exhaust discharge away from the operator. The system includes a gas block with gas channels for directing exhaust gas away from an operator and a gas plug bore configured to accommodate insertion of a gas plug. The gas plug can include an actuator for rotating the gas plug, a key that fits within a key notch and key channel inside the gas plug bore to secure the gas plug within the bore, and a regulator portion to control the flow of discharge gas from a firearm barrel. The regulator portion includes a passage with two opening segments that accept discharge gas from the barrel and direct the gas through another opening disposed in a regulator cutout and to a piston portion of the gas block.

A system for an adjustable gas block. The gas block body has a main chamber fluidly coupled to a gas aperture which is fluidly connected to a plunger channel and a gas return path. Downstream of the gas block body is a plunger assembly which includes a ring and a plunger. Further downstream is an adjustment knob which is coupled to the gas block body and which is adjustable upstream and downstream relative to the gas block body. The volume of plunger inserted into the channel path is controlled by the adjustment knob.

A system for an adjustable gas block. The gas block body has a main chamber fluidly coupled to a gas aperture which is fluidly connected to a plunger channel and a gas return path. Downstream of the gas block body is a plunger assembly which includes a ring and a plunger. Further downstream is an adjustment knob which is coupled to the gas block body and which is adjustable upstream and downstream relative to the gas block body. The volume of plunger inserted into the channel path is controlled by the adjustment knob.

A rifle with a barrel firmly mounted in a framework, the barrel including a locking sleeve, a lock, a sliding block, and a gas-powered actuator. Advantageously quiet operation of the gas-powered actuator is accomplished when the actuator has an annular piston, which is movable on a plunger support, forming an expansion chamber, where the actuator acts on the sliding block via push rods and is pushed forward by reset springs, and the rifle further includes a gas borehole penetrating the walls of the barrel and the plunger support, and further where the plunger support includes an outlet channel in its front, upper range, which is fluidly separate from the expansion chamber when the annular piston is at rest, and is fluidly connected with the expansion chamber after a backward displacement of the annular piston.

Gas tube assembles are provided for mounting on a gas block of a gas-actuated firearm having an internal passage configured to receive propellant gas from a barrel of the firearm. The gas tube assemblies have a gas tube that defines a passage extending between a forward and a rearward end of the gas tube. The gas tube assemblies also have a mating portion secured to the gas tube. The mating portion has a flange that can be secured to the gas block so that the flange prevents linear and rotational movement of the gas tube in relation to the gas block.