Barrel: 4" chrome moly steel barrel. Chambered in 9mm, (9x19), with a 1/10 twist. The barrel is nitride treated for durability and finished off with a Palmetto State Armory 5" Lightweight M-Lok free-float rail and a PSA Fluted Flash Can. Upper: Forged 7075 T6 aluminum AR-V slick side upper is hard coat anodized black for durability.  These upper receivers are made for us right here in the USA. Bolt Carrier Group: AR-V 9mm BCG.  Nitride treated 8620 steel bolt, with an enhanced firing pin and external 5.56 style extractor. The bolt carrier group is compatible with most aftermarket fire control groups.  Lower:. Forged 7075 T6 aluminum and then hard coat anodized, these lowers are purpose built to accept AR-V U9 and CZ Scorpion Magazines.  The lower is assembled with a Palmetto State Armory MOE EPT SBA3 lower build kit with a Magpul Grip and SB Tactical SBA3 Pistol Stabilizing Brace.  This product features last round bolt hold open.    #html-body [data-pb-style="62DF82895D8A5"]{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="62DF82895D8B2"]{border-style: none; border-width: 1px; border-radius: 0px; margin: 0px; padding: 0px;}