A device for converting a semiautomatic firearm to a non-semiautomatic firearm. The device includes a bolt stop lever pivotally attachable to a receiver of a firearm, a spring configured to be installed in contact with the bolt stop lever and a firearm receiver such that the spring exerts a force on the bolt stop lever to retain the bolt stop lever in a first position, and, a bolt release mechanism operatively coupleable to the bolt stop lever and configured to pivot the bolt stop lever against the force of the spring into a second position. The bolt release mechanism is operatively decoupled from the bolt stop lever when the bolt stop lever reaches the second position. When in the first position the bolt stop lever restricts motion of a bolt of the firearm, and when in the second position, the bolt stop lever permits motion of the firearm bolt.

Trigger groups for semi-automatic firearms have a hammer, a trigger element, a sear, a selector, and a disconnector assembly, the disconnector assembly operable when the selector is in a first position to retain the hammer in the cocked position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, and the disconnector assembly operable when the selector is in a second position to release the hammer to the striking position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, such that the firearm discharges once per cycle of the trigger element when the selector is in the first position, and fires once for each forward or rearward motion of the trigger element when the selector is in the second position.

Trigger groups for semi-automatic firearms have a hammer, a trigger element, a sear, a selector, and a disconnector assembly, the disconnector assembly operable when the selector is in a first position to retain the hammer in the cocked position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, and the disconnector assembly operable when the selector is in a second position to release the hammer to the striking position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, such that the firearm discharges once per cycle of the trigger element when the selector is in the first position, and fires once for each forward or rearward motion of the trigger element when the selector is in the second position.

A trigger unit for a firearm, including a trigger bar that lies below the trigger axis. A trigger lever has a rear which accommodates at least one disconnector. A sear, rotatable about a sear axis can be biased by means of a sear spring. The hammer axis, the trigger axis and the sear axis are arranged parallel to one another and parallel to a transverse direction. The trigger lever has a recess and the sear is at least partially arranged within. The sear axis and the trigger axis coincide. The sear limits rotation of a disconnector joint formed on the underside of the disconnector; the bearing encloses the disconnector joint at least partially.

A trigger unit for a firearm, including a trigger bar that lies below the trigger axis. A trigger lever has a rear which accommodates at least one disconnector. A sear, rotatable about a sear axis can be biased by means of a sear spring. The hammer axis, the trigger axis and the sear axis are arranged parallel to one another and parallel to a transverse direction. The trigger lever has a recess and the sear is at least partially arranged within. The sear axis and the trigger axis coincide. The sear limits rotation of a disconnector joint formed on the underside of the disconnector; the bearing encloses the disconnector joint at least partially.

A safety selector assembly for a firearm includes a cylinder sized and shaped to be rotatably received within a lower receiver; and a lever detachably coupled to the cylinder end and secured to the cylinder end by a threaded member. The threaded member is configured to engage the cylinder end, and to move between a first and a second position in relation to the cylinder end. The lever is configured to engage the threaded member when the threaded member is in the first position, and interfering contact between the threaded member and the lever causes the lever to be retained on the cylinder end. The lever can be removed from the cylinder end when the threaded member is in the second position.

A device for converting a semiautomatic firearm to a non-semiautomatic firearm. The device includes a bolt stop lever pivotally attachable to a receiver of a firearm, a spring configured to be installed in contact with the bolt stop lever and a firearm receiver such that the spring exerts a force on the bolt stop lever to retain the bolt stop lever in a first position, and, a bolt release mechanism operatively coupleable to the bolt stop lever and configured to pivot the bolt stop lever against the force of the spring into a second position. The bolt release mechanism is operatively decoupled from the bolt stop lever when the bolt stop lever reaches the second position. When in the first position the bolt stop lever restricts motion of a bolt of the firearm, and when in the second position, the bolt stop lever permits motion of the firearm bolt.

Trigger groups for semi-automatic firearms have a hammer, a trigger element, a sear, a selector, and a disconnector assembly, the disconnector assembly operable when the selector is in a first position to retain the hammer in the cocked position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, and the disconnector assembly operable when the selector is in a second position to release the hammer to the striking position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, such that the firearm discharges once per cycle of the trigger element when the selector is in the first position, and fires once for each forward or rearward motion of the trigger element when the selector is in the second position.

Trigger groups for semi-automatic firearms have a hammer, a trigger element, a sear, a selector, and a disconnector assembly, the disconnector assembly operable when the selector is in a first position to retain the hammer in the cocked position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, and the disconnector assembly operable when the selector is in a second position to release the hammer to the striking position in response to release of the trigger element to the rest position subsequent to discharge of the firearm by pulling the trigger element, such that the firearm discharges once per cycle of the trigger element when the selector is in the first position, and fires once for each forward or rearward motion of the trigger element when the selector is in the second position.

A modification to a trigger assembly for an AK style firearm having a trigger with sear and a disconnector pivotally coupled to the trigger, includes a secondary disconnector pivotally coupled to the trigger rearward of the disconnector and movable between a limiting position toward the disconnector and a non-limiting position away from the disconnector. A selector bar is movable between a front position, engaging the trigger to prevent rotation thereof, a middle position allowing the secondary disconnector to be biased into the limiting position engaging the disconnector, and a back position engaging the secondary disconnector and retaining the secondary disconnector in the non-limiting position against the bias and spaced from the disconnector.