Abstract: 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.

Abstract: 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.

Abstract: A magazine adapter for use in a firearm includes a magazine adapter body configured to be bottom-fed and detachably received within a magazine well on the firearm. The magazine adapter body has a bottom panel, an upwardly extending first panel and an upwardly extending second panel defining a channel therebetween proportioned to slidably receive a magazine therein. The second panel defines a groove configured to engage a firearm magazine catch on the firearm when the magazine adapter body is received within the magazine well. The magazine adapter body may detach from the magazine well when the firearm magazine catch is actuated. The first panel includes an adapter magazine catch configured to releasably engage the magazine when the magazine is received within the magazine adapter channel. A magazine release is coupled to the adapter magazine catch. The adapter magazine catch disengages from the magazine when the magazine release is actuated.

Abstract: An upper receiver and barrel assembly includes an upper receiver, a barrel assembly and a gas piston assembly. An upper receiver housing receives a shotgun shell cartridge and the bolt carrier group includes a bolt carrier, a bolt within the bolt carrier, a firing pin and an ejector pin to expel fired shells. The barrel assembly includes a barrel, a barrel extension and a barrel nut to secure the barrel and barrel extension to the upper receiver housing. The gas piston assembly includes a piston body, a piston end cap and a piston bonnet configured to slidably receive the piston end cap therein. A piston gap is defined between the piston end cap and the bonnet end wall. The barrel defines a gas port fluidly connecting the open bore of the barrel with the piston gap. A biasing member urges the piston toward the bonnet.

Abstract: A magazine adapter for use in a firearm includes a magazine adapter body configured to be bottom-fed and detachably received within a magazine well on the firearm. The magazine adapter body has a bottom panel, an upwardly extending first panel and an upwardly extending second panel defining a channel therebetween proportioned to slidably receive a magazine therein. The second panel defines a groove configured to engage a firearm magazine catch on the firearm when the magazine adapter body is received within the magazine well. The magazine adapter body may detach from the magazine well when the firearm magazine catch is actuated. The first panel includes an adapter magazine catch configured to releasably engage the magazine when the magazine is received within the magazine adapter channel. A magazine release is coupled to the adapter magazine catch. The adapter magazine catch disengages from the magazine when the magazine release is actuated.

Abstract: An upper receiver and barrel assembly includes an upper receiver, a barrel assembly and a gas piston assembly. An upper receiver housing receives a shotgun shell cartridge and the bolt carrier group includes a bolt carrier, a bolt within the bolt carrier, a firing pin and an ejector pin to expel fired shells. The barrel assembly includes a barrel, a barrel extension and a barrel nut to secure the barrel and barrel extension to the upper receiver housing. The gas piston assembly includes a piston body, a piston end cap and a piston bonnet configured to slidably receive the piston end cap therein. A piston gap is defined between the piston end cap and the bonnet end wall. The barrel defines a gas port fluidly connecting the open bore of the barrel with the piston gap. A biasing member urges the piston toward the bonnet.