Description
The CMMG A1 Receiver Extension and Stock Kit is a complete fixed buttstock and buffer-tube assembly for the AR-15 platform. Built around a classic A1-style profile, this kit gives your AR a traditional fixed stock look while providing all the supporting hardware needed for a rifle-length buffer system.
The A1 buttstock is molded from high-strength polymer in black and integrates both a rear storage compartment and a built-in sling mount for sling attachment. The included receiver extension (buffer tube) is machined from anodized aluminum to a Mil-Spec diameter, and the kit has an overall installation length of 15 inches for a rifle-length configuration.
This CMMG stock kit includes everything required to install a complete A1 fixed stock on a standard AR-15 lower with a rifle-length buffer system:
- A1 rifle-length buttstock assembly
- CMMG A1 receiver extension (buffer tube)
- Rifle buffer assembly
- Action spring
Ideal for completing a retro A1 build or refreshing a worn-out fixed stock, this CMMG 55CA646 kit supplies the major components needed to finish an AR-15 lower with a traditional fixed A1 stock setup.








