The Beretta PX4 Storm introduced rotary barrel lockup to Beretta's polymer-frame pistol line. The barrel rotates during the firing cycle to lock into the slide, a system borrowed from the Beretta Cougar. The rotation absorbs recoil energy smoothly, producing a notably soft-shooting gun for its caliber. The PX4 features replaceable backstraps, an ambidextrous safety/decocker, and a Picatinny rail. Type: Pistol Action: Semi-Automatic Caliber: 9mm Capacity: 17 Year introduced: 2004, Italy Weight: 27.7 oz Overall length: 7.6" Status: Active Intended use: Service, Law Enforcement, Home Defense, Duty / Defense