Product DescriptionThe CMMG .300 Blackout 16.1-inch Multi Role barrel sub-assembly is built for shooters assembling a custom AR-15 upper group. Made from durable 4140 chrome moly steel and finished in salt bath nitride for improved wear and corrosion resistance, this barrel is designed for reliable performance and longevity. It includes a properly installed M4 barrel extension, and the barrel sub-assemblies are properly headspaced to help streamline your build.Product Highlights 16.1-inch .300 AAC Blackout barrel sub-assembly for AR-15 upper group builds 4140 chrome moly steel construction with salt bath nitride finish (black) Multi Role profile with 1:7 twist rate for broad .300 BLK load compatibility Carbine-length gas port with 0.750-inch gas block journal Threaded 5/8x24 muzzle and includes a properly installed M4 barrel extensionSpecs Brand: CMMG Manufacturer Part Number: 30DF80A UPC: 815835011028 Caliber: .300 Blackout (300 AAC Blackout) Barrel Length: 16.1 in Material: 4140 Chrome Moly steel Finish: Salt Bath Nitride (Black) Twist Rate: 1:7 Muzzle Thread: 5/8x24 Gas System: Carbine-length gas port Gas Block Journal: 0.750 in Profile: Multi Role Extension: M4 barrel extension (installed)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 products manufacturer.