The CMMG Mk4 AR-15 stripped lower receiver in Armor Black (CMMG part no. 55CA102-AB) is a quality mil-spec lower, ready to be the foundation of your next build. CMMG precision machines it from forged 7075-T6 aluminum and finishes it in Armor Black Cerakote. As a stripped lower it comes without internal parts, so it works with any mil-spec lower parts kit, and CMMG suggests pairing it with its Gunbuilder’s Lower Parts Kit, trigger guard, pistol grip and fire control group. Every CMMG product is backed by a Lifetime Quality Guarantee against material and workmanship defects.

Key Specifications

• The platform is Mk4 AR-15, CMMG’s mil-spec pattern lower for AR-15 builds.
• The receiver is forged 7075-T6 aluminum, a strong, lightweight alloy that is common in quality lowers.
• The finish is Armor Black Cerakote, a durable coating that resists wear and corrosion.
• The lower is stripped, supplied without internal parts, so you choose the trigger, grip and the rest of the lower parts.
• It accepts any mil-spec lower parts kit, which gives wide freedom in building the rifle or pistol.
• The action type is semi-automatic, the standard configuration for an AR-15 lower.
• CMMG backs it with a Lifetime Quality Guarantee against material and workmanship defects.

Frequently Asked Questions

Is this lower receiver complete? No. It is a stripped lower, so you need a lower parts kit, trigger guard, pistol grip, fire control group and stock or brace kit to finish it.

What is it made of? CMMG machines it from forged 7075-T6 aluminum and finishes it in Armor Black Cerakote.

Which parts kits will fit? CMMG states it can be assembled using any mil-spec lower parts kit, and it suggests its own Gunbuilder’s Lower Parts Kit.

Buy the CMMG Mk4 AR-15 Stripped Lower Receiver, Armor Black

A good lower is the part of the build you only get one chance to choose, and a forged 7075-T6 CMMG Mk4 in Armor Black is a solid place to begin. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL, and browse more AR-15 lowers while you are here.