The Troy AR-15 A4 is a mil-spec AR-15 built on Troy's forged receiver set with an M1913 flattop upper, compatible with the full range of Troy's rail and sight systems. Type: Rifle Action: Semi-Automatic Caliber: 5.56x45mm NATO Capacity: 30 Year introduced: 2008, USA Weight: 63 oz Overall length: 33" Status: Active Intended use: Tactical, Home Defense