Colt's Manufacturing Colt Viper, Revolver, 357 Magnum, 4.25 Barrel, Stainless Steel Finish, Traditional Walnut Grips, Black Ramp Front Sights, U-Notch Rear Sights, 6 Rounds VIPER-SP4WRR The Colt Viper features a 1/2 lug barrel design to reduce weight and increase concealability. The forged stainless-steel construction delivers a robust shooting experience and is paired with a one-piece barrel with a recessed target crown. Chambered for 357 Magnum and accepts 38 Special Cartridges.