Bilson Arms BA-15FC 300 Blackout 12.5in Forward Complete Upper Assembly Pistol Length 1-7 Twist 5/8-24 TPI Sniper Green/Grey. 5 inch 4150/4151 CrMoV barrel with FDE & Graphite Black Cerakote Specifications for Bilson Arms BA-15FC 300 Blackout 12.5in Forward Complete Upper Assembly: Manufacturer: Bilson Arms Caliber: .300 AAC Blackout Barrel Length: 12.5 in Gas System Length: Pistol Length Barrel Twist Rate: 1-7 Firearms Threads Per Inch: 5/8x24 Finish: Cerakote Fabric/Material: 6061-T6 Aluminum Features of Bilson Arms BA-15FC 300 Blackout 12.5in Forward Complete Upper Assembly Bilson Arms patented forward charging design Package Contents: Bilson Arms BA-15FC 300 Blackout 12.5in Forward Complete Upper Assembly Comes in a plastic hard case with a gun lock and owners manual Bilson Arms P2UFC4910R1: BA-15FC 300 Blackout 12.5in Forward Complete Upper Assembly Pistol Length 1-7 Twist 5/8-24 TPI Sniper Green/Grey