Product Description The Doublestar Corp. AR-15 Bolt Carrier Group (BCG) with O-Ring is a complete, mil-spec drop-in solution designed to get your AR-15 up and running without any modification. This BCG is built to exacting standards using premium materials, featuring a 158 Carpenter Steel bolt and an 8620 steel carrier for exceptional strength and durability. The bolt undergoes batch magnetic particle inspection to ensure long service life and reliability. Both the bolt and carrier are finished in a matte black phosphate coating that provides superior resistance to heat, wear, and corrosion. The carrier is chrome lined for added durability and features a properly staked gas key for secure, long-lasting performance. The complete kit includes the bolt assembly, firing pin, firing pin retaining pin, cam pin, and the full carrier - everything you need for a fully functional BCG right out of the box. Product Highlights Mil-Spec Drop-In Fit: Drops directly into any standard mil-spec AR-15 upper receiver with no modification required. Batch Magnetic Particle Inspected Bolt: Each bolt is rigorously inspected for integrity, ensuring reliability and an extended service life. 158 Carpenter Steel Bolt: High-quality steel construction provides outstanding strength and resistance to stress under repeated firing. Chrome-Lined Carrier with Staked Gas Key: Chrome lining enhances wear resistance and ease of cleaning, while the staked gas key prevents loosening under heavy use. Black Phosphate Finish: The matte black phosphate coating on both bolt and carrier resists heat, corrosion, and wear for long-term dependability. Specs Brand: Doublestar Corp. Manufacturer Part Number (MPN): AR100 UPC: 841348103301 Type: Bolt Carrier Group Compatible Platform: AR-15 (Mil-Spec) Bolt Material: 158 Carpenter Steel Carrier Material: 8620 Steel Finish: Matte Black Phosphate Carrier Interior: Chrome Lined Gas Key: Staked Includes: Bolt Assembly, Firing Pin, Firing Pin Retaining Pin, Cam Pin, Complete Carrier 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. ]]>