The CMMG Mk4/AR15 Upper Receiver Assembly, Armor Black (CMMG part no. 55BA290AB) is expertly crafted from aircraft-grade aluminum as a base for a new AR15 build. It comes with CMMG’s ZEROED Polymer Dust Cover pre-installed, saving a step during assembly, and the receiver omits the forward assist for shooters who want a sleeker, more streamlined profile. Finished in Armor Black, it’s built to match the rest of a CMMG Mk4/AR15-pattern build. Builders starting a new upper from scratch get a lightweight, forward-assist-free receiver ready for barrel and handguard installation.

Key Specifications

• Machined from aircraft-grade aluminum.
• Ships with a ZEROED Polymer Dust Cover pre-installed.
• Omits the forward assist for a sleeker receiver profile.
• Compatible with the Mk4/AR15 receiver platform.
• Finished in Armor Black.
• Weighs approximately 0.535 pounds.

Frequently Asked Questions

Does this receiver have a forward assist? No, it omits the forward assist for a sleeker profile.

Does the dust cover come installed? Yes, the ZEROED Polymer Dust Cover ships pre-installed.

Buy the CMMG Mk4/AR15 Upper Receiver Assembly, Armor Black

Order this upper receiver from our Lubbock, Texas gun shop for fast, insured shipping, and browse the rest of our AR15 uppers selection to complete your build.