DPMS DP51655126040: Features - Barrel: Chrome Moly steel phosphate coated barrel. Chambered in 5.56 NATO with a 1/7 twist M4 barrel extension and a carbine-length gas system. Barrel is finished off with a DPMS 10.5 Lightweight M-Lok rail low-profile gas block and A2 flash hider. - Upper: Forged 7075-T6 A3 AR upper is machined to MIL-SPECS and hard coat anodized. Uppers include forward assist and dust cover. These uppers are made for us right here in the USA by a mil-spec manufacturer. - Bolt: Full-auto profile bolt carrier group. Shot-peened mil-spec Carpenter No. 15 steel bolt. Gas Key Hardened to Usgi Specifications Fastened with Grade 8 screws and Staked Per Mil-Spec. - Lower: These forged lowers are quality made using 7075-T6 aluminum and are marked Multi for caliber. Finish is hard coat anodize. Finished with a Magpul MOE Grip SB Tactical SBA3 Pistol Stabilizing Brace and 6 position 7075 buffer tube. The fire control group is a DPMS Panther Polished Trigger (PPT) single-stage assembly. - Details - Barrel Length: 11.5 - Barrel Profile: A2 - Barrel Steel: Chrome Moly Vanadium - Barrel Finish: Phosphate - Chrome Lining: No - Muzzle Thread Pattern: 1/2 x 28 - Twist Rate: 1 in 7 - Barrel Extension: M4 - Gas System Length: Carbine - Diameter at Gas Block: .750 - Gas Block Type: Low-Profile Gas Block - Muzzle Device: A2 -style - Receiver Material: Forged 7075-T6 - Receiver Type: M4 - Handguard Type: DPMS 10.5 Lightweight M-Lok - Bolt Material: Carpenter 158 Steel - Bolt Carrier Profile: Full Auto - Fire Control Group: Panther Polished Trigger (PPT) - Grip: Magpul MOE Grip Black - Buffer Tube: 7075 T6 Aluminum - Adjustment: 6 Position - Pistol Brace: SB Tactical SBA3 Pistol Stabilizing Brace