PWS MK116 with 16-inch chrome-lined barrel and PWS's long-stroke piston operating system. Unlike most piston ARs which use short-stroke systems, PWS employs a long-stroke piston that moves with the carrier, providing more consistent cycling force across the dwell cycle and greater reliability in adverse conditions. Type: Rifle Action: Semi-Automatic Caliber: 5.56 NATO Capacity: 30 Year introduced: 2009, USA Weight: 110 oz Overall length: 34.75" Status: Active Intended use: Tactical, Law Enforcement, Sport Shooting