Product DescriptionThe heart of a reliable AR-15 build is a quality 5.56 bolt carrier group (BCG) assembly, and this Angstadt Arms unit is built to deliver consistent function with a durable black nitride finish. Machined to mil-spec dimensions, the carrier is made from 8620 alloy steel and paired with a Carpenter 158 steel bolt. High pressure testing helps ensure dependable performance for hard use, training, and duty-focused AR-15 setups in 5.56 NATO / .223 Remington.Product Highlights AR-15 bolt carrier group engineered for 5.56 NATO / .223 Remington platforms Carrier machined from durable 8620 alloy steel to mil-spec dimensions Bolt machined from Carpenter 158 tool steel for strength and longevity Black nitride (QPQ) finish for enhanced wear resistance and easy cleaning High pressure tested (HPT) for added reliability and quality assuranceSpecs Brand: Angstadt Arms Product Type: Bolt Carrier Group (BCG) Platform Fit: AR-15 Caliber: 5.56x45mm NATO / .223 Remington Carrier Material: 8620 alloy steel Bolt Material: Carpenter 158 tool steel Finish: Black Nitride (QPQ) Testing: High pressure tested (HPT) UPC: 853427007776 Manufacturer Part Number: AA56BCGNITDisclaimer: 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.