Barrel: Chrome moly steel.Chambered in 300 AAC, M4 barrel extension, and a pistol-length gas system; Heavy profile barrel is finished off with a PSA 13.5" Lightweight M-Lok free-float hand guard, low-profile gas block, and A2 flash hider. Upper: Forged 7075-T6 A3 AR-15 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 Carrier Group: Full-auto profile bolt carrier group. Shot-peened, mil-spec Carpenter 158 steel bolt, Gas Key Hardened to USGI Specifications, Fastened with Grade 8 screws, and Staked Per Mil-Spec. 8620 steel M-16 profile carrier is chrome lined and phosphate coated. Lower: These forged lowers are quality made using 7075-T6 aluminum and are marked "MULTI" for caliber. Finish is hardcoat anodized. Mil-spec diameter 7075-T6 buffer tube is hardcoat anodized, has 6 adjustment positions, and is fitted with a MagpulA(R) carbine stock.;The MagpulA(R) grip complements the PSA mil-spec finished single-stage fire control group. Includes: Magpul 30rd PMAG (1); Where allowed by law. FFL required