Stevens 22439 320 Security 20 Gauge 18.50" 5+1 3" Matte Blued Matte Black Fixed Pistol Grip Stock Ambidextrous Hand (Full Size) Ghost Ring Sight. The Stevens 320 Security pump shotgun uses a proven rotary bolt design and dual slide bars. It is a bottom load, right eject, and has a tube magazine with a 5-round capacity. The 320 Security has an 18.5" carbon steel barrel with a cylinder bore and a blued metal finish. This 20 gauge model has a ghost ring sight and black synthetic buttstock with a pistol grip.