The CMMG Zeroed Lower Parts Kit Mk3 Gunbuilder’s Kit gives AR-pattern builders a focused set of premium lower receiver components tailored to the Mk3 platform. This kit centers on CMMG’s Zeroed line of controls, including an extended bolt catch, adjustable 60/90-degree ambidextrous safety, and ambidextrous magazine catch, all finished in a clean black to complement modern builds.

Ideal for new Mk3 builds or refreshing a well-used lower, this kit supplies the essential pins, detents, and springs needed to complete your receiver without unnecessary fire-control parts. The enhanced controls improve ergonomics and accessibility for both right- and left-handed shooters, making it well suited for range use, training, or competition-focused rifles. Thoughtful design and consistent quality reflect CMMG’s reputation for innovative, builder-friendly AR components.

Key Features:

• Manufacturer: CMMG
• Model: Zeroed Lower Parts Kit Mk3 Gunbuilder’s Kit
• Type: Lower receiver parts kit with ambidextrous controls
• Included Components: Zeroed extended bolt catch, 60/90 adjustable ambi safety, ambi magazine catch, pins, detents, and springs for Mk3 lowers
• Finish Color: Black