Barrel: Chrome Moly steel. Chambered in 5.56 NATO, with a 1/7 twist, M4 barrel extension, and a carbine-length gas system. Barrel is is finished off with a standard flat dark earth handguard, F-Marked gas sight base, 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. 158A(R) 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 anodize.. Mil-spec diameter 7075-T6 buffer tube is hardcoat anodized, has 6 adjustment positions, is fitted with a PSA M4 Carbine Stock. The the fire control group is a PSA mil-spec finished, single-stage assembly.#html-body [data-pb-style="62DF8287C0323"]{justify-content: flex-start; display: flex; flex-direction: column; background-position: left top; background-size: cover; background-repeat: no-repeat; background-attachment: scroll; border-style: none; border-width: 1px; border-radius: 0px; margin: 0px 0px 10px; padding: 10px;}#html-body [data-pb-style="62DF8287C0330"]{border-style: none; border-width: 1px; border-radius: 0px; margin: 0px; padding: 0px;}