The CMMG Zeroed AR-15 Lower Parts Kit (brand part no. 55CA6BA) bundles every small internal part a builder needs to finish a stripped AR-15 lower receiver, from the trigger group pins to the takedown detents and springs. Home builders and gunsmiths reach for a complete kit like this instead of sourcing dozens of tiny parts individually, since a single missing detent spring can stall a build for days. CMMG is a well-known name in AR-pattern rifle components, and this kit is built to standard AR-15 mil-spec dimensions so it drops into a typical stripped lower without fitting issues. It is a straightforward way to take a bare receiver to a finished, functional lower.

Key Specifications

• Built to complete a stripped AR-15 lower receiver, covering the small parts needed for final assembly.
• Manufactured to standard mil-spec AR-15 dimensions for drop-in compatibility.
• Sold as a gunbuilder’s kit, bundling all the small internals in one box instead of separate purchases.
• Produced by CMMG, an established name in AR-platform components and complete uppers.

Frequently Asked Questions

What does this kit include? It bundles the small internal parts needed to finish a stripped AR-15 lower, such as pins, springs, and detents.

Will it fit a standard mil-spec lower? Yes, it is built to standard AR-15 mil-spec dimensions.

Buy the CMMG Zeroed AR-15 Lower Parts Kit

Finish your build with the CMMG Zeroed AR-15 Lower Parts Kit and skip the hassle of sourcing parts one at a time. Browse more from CMMG in our AR lower parts kits category, shipped fast from our Lubbock, Texas shop.