TriStar Cobra III Marine, Pump, 12 Gauge 3, 18.5 Barrel, Silver, Synthetic, 5Rd 23164 The TriStar Cobra III is a 3 in. pump action shotgun that allows you to shoot the lightest target loads to heavy waterfowl loads. This Marine model features an 18.5" barrel, chrome lined chamber & bore, an assisted pump action and comes with a matte silver finish.