CMMG MK3 Lower Receiver Assembly – .308 Win | Armor Black

Build your next precision .308 WIN rifle on a solid foundation with the CMMG MK3 Lower Receiver Assembly in Armor Black. Engineered by CMMG — one of America’s most trusted AR-platform manufacturers — this MK3 lower receiver assembly is purpose-built for the .308 Winchester cartridge, delivering the strength, precision, and reliability that serious shooters demand.

The MK3 platform is CMMG’s large-format AR variant designed to handle the power and dimensions of .308 WIN, making it an excellent choice for hunters, long-range competitors, and tactical shooters alike. The Armor Black finish provides a durable, corrosion-resistant coating that holds up to hard use in the field or on the range.

Whether you’re completing a custom .308 build or replacing a worn component, this CMMG MK3 lower receiver assembly offers a high-quality, mil-spec-inspired foundation you can trust. Pair it with your preferred upper receiver, stock, and trigger components to create a purpose-driven rifle tailored to your needs.

Available online with fast shipping nationwide, or visit Deep Roots Rifle Co in Eustis, Florida, where our knowledgeable staff can help you plan your next custom build. We specialize in hard-to-find components and custom AR builds — stop in or order online today.