Standard M4-configuration civilian AR-15. Direct impingement, 16.1" M4-profile barrel, 1:7 twist. Law enforcement and civilian. Type: Rifle Action: Semi-Automatic Caliber: 5.56 NATO Capacity: 30 Year introduced: 2009, USA Weight: 6.36 oz Overall length: 32.5" Status: Active Intended use: home_defense, duty, law_enforcement