Smith & Wesson J-Frame revolver is designed to fire a full power round and is reliable. It is a small-frame, defense revolver. The M&P 340 is based on the classic J-frame Centennial AirLite revolver with modern, ergonomic features. It features lightweight scandium alloy frame, stainless steel barrel and cylinder, XS Sights 24/7 Tritium night front sight and an integral u-notch rear and a snag-free enclosed hammer. This model has a black finish and no internal lock.