The Browning Auto-5 was produced by legendary shotgun designer John Browning and was a recoil-operated autoloading shotgun. The shotgun was the first fully successful autoloading shotgun ever produced.
The Winchester Model 12, more formerly known as the Winchester Model 1912 (also commonly referred to as the M12 or Model 12) is a pump action or hammerless slide-action, shotgun with an external tube magazine.
The Saiga-12 is a 12 gauge Kalashnikov-pattern combat shotgun available in a wide variety of configurations. Similar to the Kalashnikov rifle variants, it is a gas operated, rotating bolt gun that is fed from a box magazine.