PWS MK111 with 11-inch chrome-lined barrel and long-stroke piston system. The compact configuration uses PWS's piston-driven operation to maintain reliability at the reduced dwell time of an 11-inch barrel, where direct-impingement systems frequently experience port pressure issues. Type: Pistol Action: Semi-Automatic Caliber: 5.56 NATO Capacity: 30 Year introduced: 2010, USA Weight: 100 oz Overall length: 26.5" Status: Active Intended use: Tactical, Law Enforcement, Vehicle Operations