Systems and methods for an adjustable gas block are described. Systems may include an adjustment subassembly. The adjustment subassembly may include a valve stem end with a front-most portion larger in diameter than the rear-most portion and a boss extending from the forward portion of the valve stem end; a valve ring surrounding the boss of the valve stem end; a valve threaded portion for receiving the boss of the valve stem end and having a threaded portion; and a valve rotator coupled to the valve threaded portion for adjusting the flow of gas. Systems may include a gas block assembly. The gas block assembly may include a gas block through hole; a first duct to direct pressurized gas from a barrel to a plenum; a second duct to direct a regulated volume of gas to a gas operating system; a seat valve to control the regulated volume of gas to the gas operating system; and a gas block threaded portion for coupling to the valve threaded portion. The adjustment subassembly may be coupled to the gas block assembly.

A trigger activated arm may use a piston moving within a cylinder to dampen gun bolt speed. In some embodiments, gun bolt motion increases pressure within the cylinder bore to dampen rearward gun bolt speed. The pressure may be high enough to unseat the cylinder creating a vent that cylinder fluid exits. In other embodiments, gun bolt motion decreases pressure within the cylinder bore to dampen forward gun bolt speed.

A firearm shell casing catching system for collecting casings ejected from a firearm includes a mounting assembly, casing deflector, and a hopper.

Provided is a firearm gas operating system. A gas block includes a cylinder housing. A gas actuation piston in the cylinder housing reciprocates between forward and rearward positions and has a head portion with a recess. A switchable gas control valve is insertable into the forward end of the cylinder housing and includes a central passageway open at forward and rear ends. A tubular extension open at opposite ends extends axially rearward from the gas control valve and is configured to be received by the piston head portion recess. Gas pressure diverted from the barrel causes the piston to reciprocate from its forward position, where the head portion recess extends over the tubular extension, to its rearward position, where the head portion recess disengages from the tubular extension, allowing gas to exhaust through the tubular extension and forward end of the control valve to atmosphere.

A reduced-energy cartridge for a chamber of a firearm includes a case and a sabot. The sabot is moveably attached to the case and supported for movement relative to the case from an unfired position to a fired position resulting from combustion within the combustion chamber. The cartridge further includes a sealing member that projects radially outward from the longitudinal axis and from the sabot. The sealing member defines a blowback boundary where the cartridge is configured to seal against an inner surface of the chamber of the firearm. A forward area of the cartridge and a rear area of the cartridge are separated by the blowback boundary. The sealing member is configured for releasably sealing against the inner surface of the chamber to regulate pressure at the forward area resulting from combustion within the combustion chamber.

Systems and methods for an adjustable gas block are described. Systems may include an adjustment subassembly and a gas block assembly, wherein the adjustment subassembly may be coupled to the gas block assembly.

Systems and methods for an adjustable gas block are described. Systems may include an adjustment subassembly. The adjustment subassembly may include a valve stem end with a front-most portion larger in diameter than the rear-most portion and a boss extending from the forward portion of the valve stem end; a valve ring surrounding the boss of the valve stem end; a valve threaded portion for receiving the boss of the valve stem end and having a threaded portion; and a valve rotator coupled to the valve threaded portion for adjusting the flow of gas. Systems may include a gas block assembly. The gas block assembly may include a gas block through hole; a first duct to direct pressurized gas from a barrel to a plenum; a second duct to direct a regulated volume of gas to a gas operating system; a seat valve to control the regulated volume of gas to the gas operating system; and a gas block threaded portion for coupling to the valve threaded portion. The adjustment subassembly may be coupled to the gas block assembly.

A reduced-energy cartridge for a chamber of a firearm includes a case and a sabot. The sabot is moveably attached to the case and supported for movement relative to the case from an unfired position to a fired position resulting from combustion within the combustion chamber. The cartridge further includes a sealing member that projects radially outward from the longitudinal axis and from the sabot. The sealing member defines a blowback boundary where the cartridge is configured to seal against an inner surface of the chamber of the firearm. A forward area of the cartridge and a rear area of the cartridge are separated by the blowback boundary. The sealing member is configured for releasably sealing against the inner surface of the chamber to regulate pressure at the forward area resulting from combustion within the combustion chamber.

In the fixed frame it has a base, in which a barrel with the axis below the level of the upper edge of the shooter's hand, a trigger, a buffer and a long ejector are attached. A pistol grip with a cartridge magazine is obliquely slid into the frame and attached. A semi-embedded moving slide, containing especially a closed launch pad, a firing pin, an obliquely placed extractor and a rob of the trigger mechanism, is inserted into the frame from above. The slide is covered from above by upper body attached to the barrel and at two points to the frame, which carries sights at the top and has elements of the hammer system placed on the lower side.

In the fixed frame it has a base, in which a barrel with the axis below the level of the upper edge of the shooter's hand, a trigger, a buffer and a long ejector are attached. A pistol grip with a cartridge magazine is obliquely slid into the frame and attached. A semi-embedded moving slide, containing especially a closed launch pad, a firing pin, an obliquely placed extractor and a rob of the trigger mechanism, is inserted into the frame from above. The slide is covered from above by upper body attached to the barrel and at two points to the frame, which carries sights at the top and has elements of the hammer system placed on the lower side.