The M&P340 is a lightweight J-frame revolver built from scandium alloy with a 1.875-inch barrel, chambered in .357 Magnum. Exceptionally light for its power level, it is a quintessential deep-cover and backup revolver despite its punishing recoil with full-power magnum loads. Type: Revolver Action: Double-Action Caliber: .357 Magnum Capacity: 5 Year introduced: 2007, USA Weight: 13.3 oz Overall length: 6.3" Status: Active Intended use: Concealed Carry