SKU 51655160233 Brand Palmetto State Armory Model Number 51655160233 UPC 51655160233 DETAILS Barrel Length: 13.7" Gas System: Mid-Length Barrel Steel: 4150V Barrel Finish: Nitride Muzzle Thread: 1/2-28 Chamber: 5.56 Twist Rate: 1:7 Barrel Extension: M4 Diameter at Gas Block: .750 Gas Block Type: Adjustable Muzzle Device: JMAC GFHC-E Pin/Weld Receiver Material: Forged 7075 T6 Receiver Type: M4 T-Marked Hand Guard Type: PSA 13" QD Bolt Carrier Group: PSA Custom Fathers of Freedom BCG by MicroBest with Sprinco Extractor Spring Bolt Steel: Carpenter 158