The CMMG Upper Receiver Assembly (part no. 55BA206AB) is built for the MK4/AR15 platform and includes a forward assist, finished in black. CMMG builds this to standard mil-spec dimensions for compatibility with common AR15 lower receivers and barrels.

Key Specifications

• Built for the MK4/AR15 platform, CMMG’s standard-pattern receiver line.
• Includes a forward assist, unlike a bare receiver without one.
• Finished in black to match standard AR15 builds.

Frequently Asked Questions

Does this include a forward assist? Yes, it’s included on this upper receiver assembly.

What platform is this built for? CMMG’s MK4/AR15 pattern, compatible with standard mil-spec AR15 lowers.

Buy the CMMG Upper Receiver Assembly

Order this CMMG upper receiver from CMMG. Ships fast from a Lubbock, TX gun shop. Browse our full AR15 uppers selection for more build options.