Troy Defense A4 Carbine with 16-inch chrome-lined barrel and Troy TRX free-float handguard. Troy Industries built its reputation manufacturing battle accessories before launching a full rifle line. The A4 uses Troy's enhanced upper receiver with integrated bolt carrier gas key and improved feed ramps. Type: Rifle Action: Semi-Automatic Caliber: 5.56 NATO Capacity: 30 Year introduced: 2010, USA Weight: 104 oz Overall length: 33" Status: Active Intended use: Tactical, Law Enforcement, Sport Shooting