The Hatfield 12 ga. semi-auto shotgun runs via a unique gas / inertia operating system that uses a gas piston to kick the bolt to send it rearward with inertia. This free floating inertia action creates less friction since the bolt is not connected to a heavy bolt carriage and action arms thus allowing the SAS to function dependably with light field loads on up to 3 magnums. Stocked with ultra-durable camo-dipped polymer for both stock and fore-end, the SAS also features a 28 chrome lined barrel vent rib barrel, with screw in chokes.