The PWS MK107 is a 7.75-inch pistol-configuration long-stroke piston AR designed for close-quarters use and suppressor mounting. The extremely short barrel benefits significantly from the piston system, which eliminates the excessive gas blowback that plagues ultra-short direct-impingement 5.56 guns. PWS's FSC556 muzzle device helps control blast at this barrel length. Type: Pistol Action: Semi-Automatic Caliber: 5.56x45mm NATO Capacity: 30 Year introduced: 2012, USA Weight: 60 oz Overall length: 21.5" Status: Active Intended use: Home Defense, Duty Use, Suppressor Host