Abstract: A firearm can have a backbone, a barrel, a swinging wedge, and a barrel latch, in accordance with one or more embodiments. The barrel latch can be in mechanical communication with the swinging wedge. The barrel latch can have a first position and a second position and the swinging wedge can be configured to maintain attachment of the barrel to the backbone when the barrel latch is in the first position and is configured to release the barrel from the backbone when the barrel latch is in the second position. Thus, the firearm can provide quick barrel changes. Other features enhance the reliability and utility of the firearm.

Abstract: A high capacity box magazine is provided. A plurality of nested followers may be adapted to nest one within another and a plurality of springs may be configured to nest one within another to facilitate the advancement of cartridges within the box magazine to a firearm. A spring cup or cups may be used to nest additional springs that work in series and are nested within each other to further reduce the required height of the springs. The reliability of a conventional lower capacity box magazine may be maintained or exceeded without requiring significantly greater length in order to accommodate the increased capacity. The high capacity box magazine typically requires less frequent magazine changes than conventional lower capacity box magazines.

Abstract: A high capacity box magazine is provided. A plurality of nested followers may be adapted to nest one within another and a plurality of springs may be configured to nest one within another to facilitate the advancement of cartridges within the box magazine to a firearm. A spring cup or cups may be used to nest additional springs that work in series and are nested within each other to further reduce the required height of the springs. The reliability of a conventional lower capacity box magazine may be maintained or exceeded without requiring significantly greater length in order to accommodate the increased capacity. The high capacity box magazine typically requires less frequent magazine changes than conventional lower capacity box magazines.

Abstract: A high capacity box magazine is provided. A plurality of nested followers may be adapted to nest one within another and a plurality of springs may be configured to nest one within another to facilitate the advancement of cartridges within the box magazine to a firearm. A spring cup or cups may be used to nest additional springs that work in series and are nested within each other to further reduce the required height of the springs. The reliability of a conventional lower capacity box magazine may be maintained or exceeded without requiring significantly greater length in order to accommodate the increased capacity. The high capacity box magazine typically requires less frequent magazine changes than conventional lower capacity box magazines.

Abstract: A firearm can have a backbone, a barrel, a swinging wedge, and a barrel latch, in accordance with one or more embodiments. The barrel latch can be in mechanical communication with the swinging wedge. The barrel latch can have a first position and a second position and the swinging wedge can be configured to maintain attachment of the barrel to the backbone when the barrel latch is in the first position and is configured to release the barrel from the backbone when the barrel latch is in the second position. Thus, the firearm can provide quick barrel changes. Other features enhance the reliability and utility of the firearm.

Abstract: A high capacity box magazine is provided. A plurality of nested followers may be adapted to nest one within another and a plurality of springs may be configured to nest one within another to facilitate the advancement of cartridges within the box magazine to a firearm. A spring cup or cups may be used to nest additional springs that work in series and are nested within each other to further reduce the required height of the springs. The reliability of a conventional lower capacity box magazine may be maintained or exceeded without requiring significantly greater length in order to accommodate the increased capacity. The high capacity box magazine typically requires less frequent magazine changes than conventional lower capacity box magazines.