Various embodiments are directed to a barrel for a firearm. In various embodiments, a barrel comprises an inner surface defining a bore configured to guide a projectile as the projectile is propelled through the bore by pressurized gas; and a barrel gas port having a gas port depth extending between a port entrance defined by the inner surface of the barrel and a port exit, wherein the barrel gas port is configured to fluidically communicate with the bore and an action of the firearm; wherein the port entrance defines a length dimension defined parallel to a longitudinal axis of the barrel and a width dimension defined perpendicular to the length dimension; and wherein the length dimension of the port entrance is greater than the width dimension of the port entrance. Various embodiments are directed to a firearm comprising the exemplary barrel.

A gas piston according to various aspects of the present technology comprises a helical groove disposed along an exterior surface. The helical groove may comprise curved edges at transitions between a crest and root of the helical groove. The helical groove allows for easier movement of the gas piston within its operating cylinder, provides enhanced resistance to particulate build up, and improves firing accuracy.

A gas piston according to various aspects of the present technology comprises a helical groove disposed along an exterior surface. The helical groove may comprise curved edges at transitions between a crest and root of the helical groove. The helical groove allows for easier movement of the gas piston within its operating cylinder, provides enhanced resistance to particulate build up, and improves firing accuracy.

A self-loading rifle comprising: an upper receiver defining a bolt passage, a bolt operable to reciprocate in the passage motivated by energy from discharge of the rifle, and a barrel extending from the upper receiver. The lower receiver is connected to the upper receiver and contains a trigger group and has a forwardly-extending support below the barrel, a tubular handguard encompassing at least a rear portion of the barrel, and is connected to the forwardly-extending support. The self-loading rifle of claim 1 in this the handguard is not directly connected to the upper receiver or to the barrel.

System for a delayed-opposed-piston gas action assembly. Specifically, the system is comprised of a bolt, a bolt carrier, a gas block, a bolt piston, and a vent piston. Each piston will have a corresponding piston cup that will act on the piston from the gas discharged from the round. Each piston will also have a corresponding spring to bring the piston back to its original position after the gas has dissipated from the system. During the process of the firearm being discharged, the two pistons will act on the bolt carrier, causing the casing of the round to be ejected from the firearm, and a new round to be loaded into the firearm, so that the firearm can be discharged again.

System for a delayed-opposed-piston gas action assembly. Specifically, the system is comprised of a bolt, a bolt carrier, a gas block, a bolt piston, and a vent piston. Each piston will have a corresponding piston cup that will act on the piston from the gas discharged from the round. Each piston will also have a corresponding spring to bring the piston back to its original position after the gas has dissipated from the system. During the process of the firearm being discharged, the two pistons will act on the bolt carrier, causing the casing of the round to be ejected from the firearm, and a new round to be loaded into the firearm, so that the firearm can be discharged again.

A self-loading rifle comprising: an upper receiver defining a bolt passage, a bolt operable to reciprocate in the passage motivated by energy from discharge of the rifle, and a barrel extending from the upper receiver. The lower receiver is connected to the upper receiver and contains a trigger group and has a forwardly-extending support below the barrel, a tubular handguard encompassing at least a rear portion of the barrel, and is connected to the forwardly-extending support. The self-loading rifle of claim 1 in this the handguard is not directly connected to the upper receiver or to the barrel.

An assembly for directing propellant gas to an action of a firearm includes a barrel and a gas block. The barrel has a plurality of gas ports that communicate with the bore of the barrel. The barrel and the gas block define a passage that receives pressurized propellant gas from the bore by way of the barrel gas ports, and directs the propellant gas to a gas port of the gas block. The plurality of barrel gas ports and the passage act as a manifold in which the propellant gas is taken from multiple locations within the barrel, combined into a single flow, and directed into the gas block via the gas block gas port. The pressurized gas is then routed to an action of the firearm by way of a gas tube and a gas key.

An assembly for directing propellant gas to an action of a firearm includes a barrel and a gas block. The barrel has a plurality of gas ports that communicate with the bore of the barrel. The barrel and the gas block define a passage that receives pressurized propellant gas from the bore by way of the barrel gas ports, and directs the propellant gas to a gas port of the gas block. The plurality of barrel gas ports and the passage act as a manifold in which the propellant gas is taken from multiple locations within the barrel, combined into a single flow, and directed into the gas block via the gas block gas port. The pressurized gas is then routed to an action of the firearm by way of a gas tube and a gas key.

A recoil assembly for a rifle includes a barrel assembly, a bolt, bolt actuator, and a buffer assembly. The barrel assembly includes a barrel secured to a barrel extension. The barrel assembly is configured to be movably received through the fore end of a receiver and to move axially relative to the upper receiver when the rifle is fired. The barrel extension is coupled to a hydraulic buffer assembly located below the barrel extension and counteracts recoil forces acting on the barrel extension when the rifle is fired. An op-rod spring is coupled to an op rod extending from a gas piston assembly on the barrel. The op-rod spring counteracts recoil forces acting the bolt actuator when the rifle is fired.