Abstract: An interchangeable element attachment system, including at least some of a bolt catch, wherein an attachment aperture is formed through a portion of an upper button portion of the bolt catch; an assist lever, wherein one or more attachment aperture engaging projections extend from a portion of an assist lever second side, within an attachment portion of the assist lever, wherein a portion of the attachment aperture engaging projection is received within at least a portion of the attachment aperture of the bolt catch, such that one or more portions of the attachment aperture engaging projection are abutted against one or more corresponding portions of the attachment aperture, and wherein an at least partially internally threaded fastener recess extends within the attachment portion; and a fastener positionable through the aligned attachment aperture and fastener recess to assist in attaching or coupling the assist lever to the bolt catch.

Abstract: A compression screw attachment system, including an attachment base having at least one projection, wherein an at least partially internally threaded compression screw recess extends from a terminal surface of the projection; at least one at least partially externally threaded compression screw, rotatable within the compression screw recess between a retracted position and an extended position; and one or more attachment elements, each having an attachment element recess, wherein a compression screw aperture is formed through the recess bottom wall, wherein if the compression screw is in the retracted position, the attachment element recess is slidably mateable with the projection of the attachment base and wherein the compression screw is threadedly rotatable to the extended position, wherein at least a portion of a head portion of the compression screw contacts a surface of the recess bottom wall and provides a force to urge the recess against the projection.

Abstract: A firearm safety selector lever, including at least some of a lever element having a head portion and an extension portion, wherein the extension portion includes an extension portion top wall and an extension portion sidewall; a visual element recess extending from an open first end formed in a terminal sidewall portion of the extension portion sidewall through at least a portion of the extension portion; a primary viewing aperture extending from the extension portion top wall to at least a portion of the visual element recess; and a visual element at least partially positionable within the visual element recess such that at least a portion of the visual element is viewable through the primary viewing aperture.

Abstract: A takedown pin for a firearm, having at least some of a head; a shank, wherein the shank extends from the head to a terminal surface; a projection extending from at least a portion of the terminal surface; a first groove or slot formed in at least a portion of the shank; a second groove or slot formed in at least a portion of the shank, wherein the first end of the first groove or slot is positioned at a spaced apart location from the first end of the second groove or slot; and a connecting groove or slot formed between the first end of the first groove or slot and the first end of the second groove or slot.

Abstract: A modular muzzle device adapter system having an adapter, wherein the adapter comprises an adapter body portion and an adapter projection portion, wherein the adapter includes an adapter barrel aperture formed so as to extend through the adapter; and a muzzle device, wherein the muzzle device comprises a muzzle device body portion and a muzzle device recess, wherein the muzzle device is repeatably securable to and removable from the adapter, via at least some interaction between the adapter projection portion of the adapter and the muzzle device recess of the muzzle device.

Abstract: A safety selector lever, including at least some of a lever element having a head portion and an extension portion, the extension portion includes an extension portion top wall, two extension portion sidewalls, and an extension portion bottom wall, a visual element recess is formed through at least a portion of the extension portion, at least a primary viewing aperture extends from the extension portion top wall to at least a portion of the visual element recess, and a securing screw aperture extends from the extension portion bottom wall to the visual element recess; a visual element is at least partially positionable within the visual element recess; and a securing screw is rotatably engageable within at least a portion of the securing screw aperture, such that a terminal end of the securing screw extends to contact at least a portion of the visual element within the visual element recess.

Abstract: A magazine release button assembly for a firearm, including at least some of a button member, wherein the button member includes a projection extending from an end of the button member, and wherein the projection comprises a dovetail projection; and a finger pad member, wherein the finger pad member includes a recess, wherein the recess comprises a dovetail recess, wherein the dovetail recess is mateable with the dovetail projection of the button member, and wherein the finger pad member is secured to the end of the button member via interaction of the dovetail projection and the dovetail recess.

Abstract: A charging assembly having at least a charging bar with a protrusion having a bolt carrier engaging shoulder formed by the protrusion, a gas tube aperture formed through the charging bar protrusion, a first charging bar channel formed from a first end to the charging bar protrusion and a second charging bar channel formed from the charging bar protrusion to the second end, the gas tube aperture provides an aperture between the charging bar channels; a handle element removably attached or coupled to the charging bar; at least a portion of the charging bar is positionable within at least a portion of an upper receiver of the firearm and extends into a firearm handguard and the bolt carrier engagement shoulder is positioned to engage a shoulder of a bolt carrier; and wherein the handle element extends from the charging bar, through a handle element aperture formed through the handguard.

Abstract: An interchangeable safety selector, including at least some of a generally cylindrical lock member rotatable between at least a safe and at least one fire position; at least one recess formed in each end of the lock member; and at least two lever members, each lever member having at least one projection mateable with the at least one recess of the lock member, wherein the lever members are interchangeable, and wherein at least one of the lever members is securable to a first end of the lock member via interaction of the at least one projection and the at least one recess.

Abstract: A magazine release blocking system including a blocking element and a magazine release, wherein the blocking element is positionable at least partially within a blocking element channel extending between an upper surface of a lower receiver and a magazine release button receiving cavity or a magazine release receiving cavity, and wherein the blocking element is movable between a disengaged position and an engaged position, wherein if the blocking element is in the engaged position, at least a portion of the blocking element extends such that at least a portion of the blocking element inhibits movement of the magazine release or the magazine release button, and wherein if an upper receiver of the firearm is operably positioned atop the lower receiver a surface of the upper receiver urges the blocking element to the engaged position.

Abstract: A charging handle having a charging handle body including a base portion; a handle element slidably and at least partially rotatable relative to said base portion; and a latch element slidable and at least partially rotatable relative to said handle element, and wherein at least a portion of said latch element is formed so as to interact with at least a portion of said handle recess such that rotational or longitudinal movement of said handle element relative to a longitudinal axis of said charging handle produces lateral, translational movement of said latch element relative to said charging handle body.