A modular firearm grip assembly has a frame defined by a front grip strap and a rear grip strap. The front grip strap defines a front lateral attachment point and rear lateral attachment point, and the rear grip strap has a first attachment coupling interface. A grip extension defined by a front extension strap and a rear extension strap is coupled to the frame at the respective one of the front lateral attachment point and the rear lateral attachment point thereof. The grip extension includes a second attachment coupling interface engaged to the first attachment coupling interface of the frame.

A bolt catch lever for a firearm, including receivers and associated elements for receiving the bolt catch lever. In particular, a bolt catch lever comprising an upper lever arm, a lower lever arm, and a center element including a catch which is designed so as to be pivotable about a pivot axis in a lower receiver, where the center element has a recess for optionally receiving a connection section of a second bolt catch lever.

This disclosure describes systems, methods, and apparatus for an ejection port cover allowing tool less insertion and removal. This is accomplished via a fixed pin and a spring-loaded pin that both mate with hinge openings at ends of the ejection port. The spring-loaded pin can be longitudinally biased by a spring, such as a torsion spring. This same spring can perform biasing of the ejection port cover toward an open position as well as biasing of a flag extending from the spring-loaded pin into a locked position when the ejection port cover is not installed.

This disclosure describes systems, methods, and apparatus for an ejection port cover allowing tool less insertion and removal. This is accomplished via a fixed pin and a spring-loaded pin that both mate with hinge openings at ends of the ejection port. The spring-loaded pin can be longitudinally biased by a spring, such as a torsion spring. This same spring can perform biasing of the ejection port cover toward an open position as well as biasing of a flag extending from the spring-loaded pin into a locked position when the ejection port cover is not installed.

Various embodiments are directed to ambidextrous firearm controls, including an ambidextrous bolt control assembly and/or ambidextrous magazine release and associated methods. The ambidextrous bolt control assembly may include a bolt catch configured to hingedly connect to a firearm to rotate between a disengaged position and an engaged position, the bolt catch may include a first bolt catch engagement button operable from a first side of the firearm and a first bolt catch release button operable from the first side of the firearm; an ambidextrous bolt catch engagement button operable from a second side of the firearm; and an ambidextrous bolt catch release button operable from the second side of the firearm; wherein the ambidextrous bolt catch engagement button and the ambidextrous bolt catch release button may each be separately movable relative to the firearm. The ambidextrous bolt catch assembly may further include an ambidextrous magazine release assembly.

An optical apparatus flexible stop has a flexible surface element, which is flat/planar in a first state and rolled or wound into a hollow roll in a second state. Two tensioning cords guide around the hollow roll to hold the hollow roll shape. An optical apparatus is provided with a tubular body containing an optical unit and having a first open tube end, an attachment device having a device housing, wherein an optical through passage of the device housing is arranged in front of the open tube end, and the flexible stop. The flexible stop is rolled or wound around the open tube end of the tubular body and the optical through passage of the device housing, held in the shape of a tube with the tensioning cords, thus forming an optical tunnel between the open tube end and the optical through passage.

An optical apparatus flexible stop has a flexible surface element, which is flat/planar in a first state and rolled or wound into a hollow roll in a second state. Two tensioning cords guide around the hollow roll to hold the hollow roll shape. An optical apparatus is provided with a tubular body containing an optical unit and having a first open tube end, an attachment device having a device housing, wherein an optical through passage of the device housing is arranged in front of the open tube end, and the flexible stop. The flexible stop is rolled or wound around the open tube end of the tubular body and the optical through passage of the device housing, held in the shape of a tube with the tensioning cords, thus forming an optical tunnel between the open tube end and the optical through passage.

A gun/hand muff for protecting portions of a gun user's hand, wrist, and/or forearm from the elements is provided. The gun/hand muff defines an interior cavity for ultimately receiving portions of a gun and portions of at least a gun user's hand and possibly portions of the gun user's wrist and forearm therein. The interior cavity is used to protect portions of the gun and the gun user's hand (and possibly portions of the gun user's wrist and forearm) from the elements, while simultaneously affording contact of the gun user's hand with the portions of the gun received in the interior cavity.

A gun/hand muff for protecting portions of a gun user's hand, wrist, and/or forearm from the elements is provided. The gun/hand muff defines an interior cavity for ultimately receiving portions of a gun and portions of at least a gun user's hand and possibly portions of the gun user's wrist and forearm therein. The interior cavity is used to protect portions of the gun and the gun user's hand (and possibly portions of the gun user's wrist and forearm) from the elements, while simultaneously affording contact of the gun user's hand with the portions of the gun received in the interior cavity.

A combined firearm receiver and rail includes a handguard rail and a receiver housing disposed within the handguard rail. The handguard rail includes one of a takedown lug clearance slot, a handguard magazine port, a handguard continuous rail, a handguard ejection port, an attachment location, accessory attachment points, a handguard charging handle latch retaining slot, a charging handle housing, a charging handle guideway, a bolt catch clearance slot, a barrel cavity, a receiver cavity, an exhaust port, and a handguard section. In one variation, the handguard section does not come into physical contact with a barrel or a barrel nut of the firearm.