CMMG Receiver Extension Kit Carbine AR-15 (Mil-Spec)

This CMMG receiver extension kit provides the components needed to complete a carbine-style AR-15 lower and accepts standard Mil‑Spec carbine stocks. The kit is supplied as a six-position, collapsible receiver extension with components intended for carbine use. Components include the buffer tube, carbine buffer assembly, action spring, castle nut, and receiver end plate, and the tube is finished for a black appearance.

Key Specifications

• The receiver extension is 6-position and adjustable for carbine-style stocks.
• The main construction material is aluminum.
• The exterior finish is black (hard coat anodized).
• The kit includes a Mil-Spec carbine buffer tube.
• The kit includes a carbine buffer and action spring.
• The kit includes a castle nut and receiver end plate.
• The product is designed to fit AR-15 lowers.
• The package or product dimensions are 1.75 x 6.60 x 13.05 (as supplied).

Designed to streamline completing or building an AR-15 carbine lower, this CMMG kit supplies the key buffer-system parts in a single package so you can install a Mil‑Spec carbine stock and finish your lower with components that match common AR‑15 standards. The straightforward, workmanlike design makes it a practical choice for builders and installers who want the necessary parts in a single, compatible kit.