PWS MK107 with 7-inch chrome-lined barrel and PWS long-stroke piston system. The ultra-short configuration demonstrates the reliability advantage of piston operation at extreme barrel lengths where direct-impingement systems frequently experience excessive back-pressure and inconsistent extraction. Type: Pistol Action: Semi-Automatic Caliber: 5.56 NATO Capacity: 30 Year introduced: 2012, USA Weight: 92 oz Overall length: 22" Status: Active Intended use: Tactical, Law Enforcement, Vehicle Operations