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.