SKU 5165490918 Brand Palmetto State Armory Model Number 5165490918 UPC 5165490918 DETAILS Barrel Length: 11.5" Barrel Profile: A2 Barrel Steel: Chrome Moly Vanadium Barrel Finish: Nitride Chrome Lining: No Muzzle Thread: 1/2-28 Chamber: 5.56 NATO  Twist Rate: 1:7 Barrel Extension: M4 Diameter at Gas Block: .750 Gas Block Type: Low-profile Muzzle Device: A2 Flash Hider Receiver Material: Forged 7075 T6 Receiver Type: A3 Handguard Type: Lightweight M-Lok 10.5" Free Float Rail Bolt Carrier Group Included: Yes Bolt Steel: Carpenter 158 Bolt Carrier Profile: Full-auto