Smith & Wesson 340PD DOADescription Smith & Wesson J Frame revolvers have had your back since 1950. These small revolvers were designed to fire a full power round and are as simple and easy to use as they are reliable. Available in various calibers and with three diverse hammer designs, it is no surprise that the Smith & Wesson J Frame has become the most popular, small frame, defense revolver on the market. The Model 340 PD is a variation of the Model 40 Centennial AirLite