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-operated firearms, in which the gas system guides gas selectively from the gas removal bore to a gas pipe, with a platelet, movable between at least two positions in the gas system. The platelet may be pivotable about a pivot axis pin. A stop pin, parallel to the pivot axis pin, may protrude into a stop bore of the platelet, thus delimiting the pivoting. The platelet may have at least two recessed catch positions, into which a catch, under the effect of a catch spring, optionally engages, provided that the gas through-bore associated with the catch comes to rest in alignment between the gas bores when the catch engages in one of the recesses.

Gas-operated firearms, in which the gas system guides gas selectively from the gas removal bore to a gas pipe, with a platelet, movable between at least two positions in the gas system. The platelet may be pivotable about a pivot axis pin. A stop pin, parallel to the pivot axis pin, may protrude into a stop bore of the platelet, thus delimiting the pivoting. The platelet may have at least two recessed catch positions, into which a catch, under the effect of a catch spring, optionally engages, provided that the gas through-bore associated with the catch comes to rest in alignment between the gas bores when the catch engages in one of the recesses.

A regulated gas block assembly may include a gas block including a barrel receiving bore, a gas tube receiving bore, and an intermediate passage extending from the barrel receiving bore to the gas tube receiving bore. The intermediate passage may be oriented at an oblique angle with respect to the barrel receiving bore. The intermediate passage may include a gas regulator seat, and a gas regulator may be positioned and removably secured in the gas regulator seat. A barrel including a gas ring recess may be fit to the regulated gas block assembly.

A regulated gas block assembly may include a gas block including a barrel receiving bore, a gas tube receiving bore, and an intermediate passage extending from the barrel receiving bore to the gas tube receiving bore. The intermediate passage may be oriented at an oblique angle with respect to the barrel receiving bore. The intermediate passage may include a gas regulator seat, and a gas regulator may be positioned and removably secured in the gas regulator seat. A barrel including a gas ring recess may be fit to the regulated gas block assembly.

A gas piston assembly comprises a piston apparatus having a first end and a second end. A piston bonnet has a bonnet end wall with a bonnet aperture defined therethrough and a bonnet sidewall to receive the second end of the piston apparatus therein. A piston gap is between the second end of the piston apparatus and the bonnet end wall and communicates with the bonnet aperture. An adjustable gas regulator communicates with the bonnet aperture and selectively occludes the bonnet aperture in fully open, partially open and fully closed orientations. The bonnet end wall includes a threaded bore in communication with the bonnet aperture. The gas regulator includes a threaded shaft received within the threaded bore which translates to selectively occlude the bonnet aperture. The threaded shaft includes a head portion gripped by a user while a detent engages a recess on a bottom face of the head portion.

A gas piston assembly comprises a piston apparatus having a first end and a second end. A piston bonnet has a bonnet end wall with a bonnet aperture defined therethrough and a bonnet sidewall to receive the second end of the piston apparatus therein. A piston gap is between the second end of the piston apparatus and the bonnet end wall and communicates with the bonnet aperture. An adjustable gas regulator communicates with the bonnet aperture and selectively occludes the bonnet aperture in fully open, partially open and fully closed orientations. The bonnet end wall includes a threaded bore in communication with the bonnet aperture. The gas regulator includes a threaded shaft received within the threaded bore which translates to selectively occlude the bonnet aperture. The threaded shaft includes a head portion gripped by a user while a detent engages a recess on a bottom face of the head portion.

A firearm including a barrel, receiver, indirect gas system and an adjustable gas block designed to interface with the indirect gas system is provided. Four indexable positions of adjustment are provided for on the adjustable gas block. Positions of adjustment are selected based on the use of a silencer, use of under-powered ammunition, the presence of un-burnt powder and debris in the host firearms operating system, or if the weapon is being fired under “ideal” circumstances. The provided gas block is designed to function with an indirect gas operating system. Excess gas from the operating system is not vented from the gas block thereby generating excess flash and sound. No tool is required to manipulate the adjustment mechanism of the gas.

A firearm including a barrel, receiver, indirect gas system and an adjustable gas block designed to interface with the indirect gas system is provided. Four indexable positions of adjustment are provided for on the adjustable gas block. Positions of adjustment are selected based on the use of a silencer, use of under-powered ammunition, the presence of un-burnt powder and debris in the host firearms operating system, or if the weapon is being fired under “ideal” circumstances. The provided gas block is designed to function with an indirect gas operating system. Excess gas from the operating system is not vented from the gas block thereby generating excess flash and sound. No tool is required to manipulate the adjustment mechanism of the gas.

Techniques and architectures are disclosed for a gas operating system for a firearm. The system includes a barrel having a bore including a rifled portion. Attached to the barrel is a gas block. Located distally of the rifled portion of the bore is a gas expansion chamber in fluid communication with the bore and the gas block. In some examples, the gas expansion chamber includes a diameter at least twice the bore diameter. The gas block of the gas operating system, in some examples, includes a piston, where in response to receiving gases from the gas expansion chamber, the piston cycles the gas operating system.