Product DescriptionCMMG's Barrel Sub-Assembly is built for builders who want a durable, accurate AR-15 upper foundation in hard-hitting .350 Legend. This 16.1-inch barrel is made from 4140 chromoly steel and treated with a black nitride (salt bath nitride) finish for corrosion resistance and long service life. It features a carbine-length gas system with a medium taper profile, and arrives with a properly installed M4 barrel extension to support reliable fitment and performance in compatible AR-15/Mk4 upper assemblies.Product Highlights 16.1-inch .350 Legend AR-15 barrel sub-assembly ideal for custom builds or barrel replacement 4140 chromoly steel construction with black nitride (salt bath nitride) finish for enhanced durability Carbine-length gas system with medium taper profile for balanced handling Threaded muzzle (1/2x28) and 1:16 twist rate to match common .350 Legend setups Includes properly installed M4 barrel extension; factory headspaced (per published specs)Specs Brand: CMMG Manufacturer Part Number: 35D5F0A UPC: 816422027477 Caliber/Chamber: .350 Legend Barrel Length: 16.1 in Material: 4140 chromoly steel Finish: Black nitride / salt bath nitride (matte black) Gas System Length: Carbine Profile: Medium taper Twist Rate: 1:16 Muzzle Thread: 1/2x28 Gas Journal Diameter: 0.750 in Platform Compatibility: AR-15 (CMMG Mk4/AR-15 uppers) Barrel Extension: M4 (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 product's manufacturer.