A5 Browning Magnum- 12 Gauge

The Browning Auto-5 is a long-recoil operated semi-automatic shotgun. Shells are stored in a tubular magazine under the barrel. When a chambered shell is fired, the barrel and bolt recoil together (for a distance greater than the shell length) and re-cock the hammer. As the barrel returns forward to its initial position the bolt remains behind and thus the spent shell is ejected through a port on the top of the receiver. Then the bolt returns forward and feeds another shell from the magazine into the action. This type of long recoil action was the first of its kind and patented in 1900 by John Browning.