Fostech Complete BCG Nitride for Echo AR-II Echo Sport 223 556 300BLK

The FosTech Complete Bolt Carrier Group from Fostech delivers a robust, full-auto M16 cut bolt carrier assembly designed to function reliably with the Echo AR-II and Echo Sport, featuring a Black Nitride finish for enhanced hardness and corrosion resistance. The bolt, shot peened, magnetic particle inspected, and marked, uses 9310 alloy steel with compatibility for .223, 5.56, and 300BLK applications, while the extractor is a shot peened hardened tool steel paired with a Viton Mil-Spec O-ring and three Mil-Spec gas rings to ensure consistent seal and timing. The bolt carrier itself is a heavy profile M16 style built from 8620 steel, preferred for most AR-15 builds, with properly torqued and staked Grade 8 gas key screws and a gas key composed of 4130 steel, both finished in Black Nitride to align with the overall durability. Additional components include a 4140 steel cam pin and a 8740 steel, centerless ground, hard chrome plated firing pin, weighing 11.6 ounces to balance performance and reliability. Proudly 100% USA made, this complete BCG is engineered to maximize accuracy, feed reliability, and longevity in demanding field and range use.