Semi-automatic rifle including a free floating barrel with a muzzle located at a distal end and an engagement mechanism at a proximal end. The barrel has a length measured from the proximal end to the distal end. A receiver can be configured to couple the engagement mechanism of the barrel and a bolt at least partially rotatably mounted relative to the receiver. A gas cylinder system being coupled to the barrel substantially close to the muzzle and including an operating rod. A trigger assembly coupled to the receiver to receive at least a portion of the operating rod and a bridge coupled to the trigger assembly. A fire control located substantially within the trigger assembly and configured to actuate the bolt so as to eject a cartridge and load a subsequent cartridge from a clip.

Semi-automatic rifle including a free floating barrel with a muzzle located at a distal end and an engagement mechanism at a proximal end. The barrel has a length measured from the proximal end to the distal end. A receiver can be configured to couple the engagement mechanism of the barrel and a bolt at least partially rotatably mounted relative to the receiver. A gas cylinder system being coupled to the barrel substantially close to the muzzle and including an operating rod. A trigger assembly coupled to the receiver to receive at least a portion of the operating rod and a bridge coupled to the trigger assembly. A fire control located substantially within the trigger assembly and configured to actuate the bolt so as to eject a cartridge and load a subsequent cartridge from a clip.

A gas operating system for automatic cycling of a pistol-caliber firearm is disclosed. The disclosed system may be configured to utilize gas produced by combustion of pistol cartridge propellant to automatically cycle the firearm. To that end, the disclosed system may include a gas block which routes high-pressure gas from the barrel through a gas port to a piston. The location of the gas port may be selected to lie within a region of the barrel which generally corresponds with the peak of the pressure curve associated with a given pistol cartridge. The high-pressure gas may impinge on the piston head, forcing the piston rearward and into physical contact with a short-stroke operating rod affixed to the bolt carrier of the host firearm. Consequently, the bolt carrier may be driven rearward, allowing for cycling of the firearm to progress.

A suppressor has a central expansion chamber and a coaxial expansion chamber. A front cap has at least one port in fluid communication with the coaxial chamber and an adjustable cover selectively movable between a closed position, in which the cover closes each port, and an open position, in which each port is open, thereby allowing selective control of the flow of gases and particulates exiting the coaxial chamber through each port.

A gas block for AR-platform firearms is provided which is easier to install and index on a barrel of the firearm by utilizing a wedge (e.g., collet) system. The body of the gas block may therefore be relatively precisely circular, allowing for easy movement into position on the barrel of the firearm. The gas block is stronger, tighter, more durable, and more reliably stays in place than prior art gas blocks. In one embodiment, the gas block eliminates forward gas leakage from between the gas block and barrel. The gas block is interchangeable with standard prior art gas blocks commonly found on barrels of existing AR-platform firearms. The gas block is also compatible with low profile and MLOK handguards for AR-platform firearms.

An operating system for a firearm includes a body, configured to be mounted to a firearm, having an interior space, a front, and an opposed rear. A piston is carried within the interior space for reciprocation between a forward position toward the front and a rearward position toward the rear. A gas port is formed proximate to the front of the body, and an outlet is formed proximate to the rear of the body. First and second gases flank the piston. Those first and second gases are isolated from each other. The piston moves to the rearward position in response to expansion of the first gas, thereby imparting movement of the second gas through the outlet. The piston also moves to the forward position in response to contraction of the first gas, assisted by a spring.

A firearm using blowback action has a barrel which is movably mounted within a shroud which is fixedly mounted on the firearm's frame. A gas space is formed between the barrel and the shroud by a difference between the inner diameter of the shroud and the outer diameter of the barrel. At least one gas port provides fluid communication between the bore of the barrel and the gas space. During firing of a cartridge, pressurized gas in the gas space applies a force to the barrel which moves relatively to the shroud away from the muzzle end of the firearm to engage a slide or bolt, helping to move it out of battery and extract the spent cartridge casing. Gas is vented to the atmosphere through a gas vent defined between the barrel and the shroud in fluid communication with the gas space.

A firearm using blowback action has a barrel which is movably mounted within a shroud which is fixedly mounted on the firearm's frame. A gas space is formed between the barrel and the shroud by a difference between the inner diameter of the shroud and the outer diameter of the barrel. At least one gas port provides fluid communication between the bore of the barrel and the gas space. During firing of a cartridge, pressurized gas in the gas space applies a force to the barrel which moves relatively to the shroud away from the muzzle end of the firearm to engage a slide or bolt, helping to move it out of battery and extract the spent cartridge casing. Gas is vented to the atmosphere through a gas vent defined between the barrel and the shroud in fluid communication with the gas space.

An automatic weapon system including a gas evacuation opening formed in a bore of a barrel, a gas evacuation chamber, a barrel immobilizing device, a slide, a weapon frame with guides for guiding slide movement, a return spring mechanism of the slide and the breech. The gas evacuation chamber is disposed at a near-bore space located at the barrel bore outlet, a front wall of the chamber located at the barrel bore outlet is attached at the barrel outlet and having a lower part resting on a weapon frame. A rear wall of the chamber is formed by at least one bridge assembly having one end attached to the slide and another end sliding along the barrel, the bridge assembly is formed by a substantially flat plate having a groove extending from the barrel to the frame and sliding along the barrel, at least one sealing gasket. The frame of the weapon serves as the lower part of the evacuation chamber, the slide serves as upper and side walls of the chamber, a downwardly directed ledge provided at the front of the slide.

A gas block for a firearm and a gas block system for a firearm. The gas block includes an upper tube connected to a lower tube. The upper tube includes a first passageway and an aperture through the upper tube opposite the lower tube. The lower tube includes a second passageway configured to receive a barrel of a firearm. A central passageway connects the first passageway to the second passageway. A gas nipple having a central bore is threaded into the central passageway. The gas nipple includes an engagement feature to engage a tool for the rotation of the gas nipple within the central passageway. The tool may be inserted through the aperture in the upper tube. The gas nipple may include a taper at the second end. The first passageway is configured to receive a gas tube, or a piston cup, and the second passageway receives a firearm barrel.