CMMG .350 Legend Barrel Sub-Assembly, Carbine-Length

Description

The CMMG Barrel Sub-Assembly is an AR-15-compatible upper component chambered for the .350 Legend cartridge and intended for use in Mk4/AR-15 upper builds. It ships as a properly headspaced sub-assembly with an installed M4 barrel extension and a carbine-length gas system. The barrel is finished with a nitride (SBN) treatment and features a medium taper profile and a threaded muzzle for standard muzzle devices. This part is designed to accept a .750″ gas block journal and is listed as compatible with standard 5.56/.223 bolt carrier groups in manufacturer notes.

Key Specifications

• The caliber is .350 Legend.
• Manufacturer listings include the barrel length as both 16.1 inches and 16.0 inches in different sources.
• The twist rate is 1:16".
• The finish is listed as nitride (SBN).
• The muzzle is threaded with 1/2-28 threads.
• The gas system is a carbine-length gas port with a .750″ gas block journal.
• Manufacturing notes reference construction from 4140CM steel in some sources and 416SS (blackened) in others.
• The unit ships with a properly installed M4 barrel extension and is listed as using standard 5.56/.223 BCGs.
• The weight is listed as 1 lb 9 oz.
• The contour/profile is a medium taper suitable for carbine-length builds.

This CMMG Barrel Sub-Assembly delivers the practical feature set expected for assembling a reliable AR-15 upper: compatibility with Mk4 uppers, a carbine-length gas system, a medium taper contour, and a nitride surface treatment for wear resistance. Its threaded muzzle and common gas-block journal size simplify integration into custom builds, while the installed M4 extension and headspacing expedite installation. For builders seeking a straightforward, AR-15-compatible barrel sub-assembly in .350 Legend, this component provides the core attributes necessary for a variety of carbine-style projects.