Description
The CMMG 55CA65A Receiver Extension Kit is a complete drop-in buffer system for assembling an AR-15 pistol lower or refreshing the rear of an existing build. This kit bundles every component required to finish the back end of a pistol lower in one box, eliminating the guesswork of sourcing individual parts.
At the heart of the kit is a pistol-length buffer tube machined from aluminum and finished in a durable matte black anodized coating. It is paired with a carbine-weight buffer assembly and a carbine action spring, a proven combination for reliable cycling on 5.56 NATO and .300 AAC Blackout AR-pistol platforms.
Rounding out the kit is an ambidextrous sling mount end plate, which provides a secure attachment point for sling swivels and accepts a sling from either side of the firearm. The included components install using standard tools and mate with any mil-spec AR-15 lower receiver, making this an ideal choice for new pistol builds or as a quality replacement for worn factory components.
Your purchase includes:
- Pistol buffer tube (aluminum, black finish)
- Carbine buffer assembly
- Carbine action spring
- Ambidextrous sling mount end plate








