Product DescriptionThe Noveske 5.56 Bolt Carrier Group is built for dependable performance in AR-15 platforms and is designed around proven mil-spec standards. This complete bolt carrier group features a full auto carrier with a properly staked gas key for reliable function under demanding use. The bolt is machined from Carpenter 158 steel, then shot peened and magnetic particle tested to help ensure long-term durability and consistent operation. Finished with a black phosphate carrier and chrome-lined gas key and carrier bolt bore, this BCG is suited for standard cartridges such as 5.56mm and .300 Blackout.Product Highlights Complete 5.56 bolt carrier group designed for AR-15 rifles Full auto profile carrier with staked gas key for reliable cycling and retention Bolt machined from Carpenter 158 steel for strength and long service life Shot peened and magnetic particle tested bolt for enhanced durability and quality control Black phosphate finish with chrome-lined gas key and carrier bolt bore for corrosion resistance and smooth performance Specs Product Type: Bolt Carrier Group Platform Compatibility: AR-15 Caliber Compatibility: 5.56mm, .300 Blackout Carrier Style: Full Auto Gas Key: Staked Finish: Black Phosphate Material: Steel Bolt Material: Carpenter 158 Steel Testing: Shot Peened, Magnetic Particle Tested Gas Key and Carrier Bore: Chrome Lined Mil-Spec: Yes Country of Manufacture: United States UPC: 840906108895 Manufacturer Part Number: 05000429 Brand: Noveske Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&';s manufacturer.