With a staggering 22+1 capacity, the M&P5.7 introduces a new and innovative technology - the Tempo Barrel System. Using the ballistics of the 5.7x28mm round, the rotating 5" Tempo Barrel gives you the repeatability you need to take control and feel the fast. Internal hammer-fired, gas-operated, locked-breech TEMPO(TM) barrel system (barrel doesn't cam open until bullet passes gas port). Slim, optimally textured grip. Ambidextrous slide stop. Reversible magazine release. Slide cut for optics. Flat face trigger for consistent finger placement that allows for more accurate and repeatable shooting. Picatinny-style equipment rail. Forward slide serrations. Crisp single-action trigger break. Accurate 1 in 9" twist barrel.