Bilson Arms BA-15FC 300 Blackout 16in Forward Complete Upper Assembly Mid Length 1-7 Twist 5/8-24 TPI Fde/Sniper Green. 300 AAC Blackout Barrel Length: 16 in Gas System Length: Mid Length Barrel Twist Rate: 1-7 Threads per Inch: 5/8x24 Finish: Cerakote Fabric/Material: 6061-T6 Aluminum Features of Bilson Arms BA-15FC 300 Blackout 16in Forward Complete Upper Assembly Bilson Arms patented forward charging design Package Contents: Bilson Arms BA-15FC 300 Blackout 16in Forward Complete Upper Assembly Comes in a plastic hard case with a gun lock and owners manual Bilson Arms A2UFCFG10R1: BA-15FC 300 Blackout 16in Forward Complete Upper Assembly Mid Length 1-7 Twist 5/8-24 TPI Fde/Sniper Green