Full rifle-length Mk4 AR in .22 LR. 16-inch barrel, carbine stock, A2 grip. Radial Delayed Blowback. Type: Rifle Action: Semi-Automatic Caliber: .22 LR Capacity: 25 Year introduced: 2015, USA Weight: 6.5 oz Overall length: 32.25" Status: Active Intended use: plinking, training, competition