CMMG AR-15 Carbine Collapsible Stock Kit 6-Position Mil-Spec

The CMMG AR-15 Carbine Receiver Extension and Stock Kit bundles all of the major hardware needed to complete a mil-spec carbine buffer system on a standard AR-15 lower. Designed and assembled by CMMG, this kit takes the guesswork out of sourcing matching components so every piece is correctly dimensioned for a clean, drop-in installation on a carbine-class build.

The kit centers on a 6-position M4-style collapsible buttstock with the familiar ribbed cheek slope and a rear sling loop, paired with a CMMG 6-position mil-spec receiver extension (buffer tube). The buttstock rides smoothly across the tube's detent positions, letting the shooter dial in length of pull for body armor, cold-weather layers, or compact storage. A mil-spec buffer tube castle nut and a matching receiver endplate round out the package, so installation only requires staking the castle nut and torquing the endplate screws.

The black finish blends with factory AR components, and the mil-spec tube diameter keeps the kit broadly compatible with the wider AR-15 aftermarket, including standard carbine and many intermediate-length applications. Total assembled length is approximately 15 inches, in line with a standard carbine-class stock and tube assembly.

Kit Includes:

• CMMG 6-position M4 collapsible buttstock assembly
• CMMG 6-position mil-spec receiver extension (buffer tube)
• Mil-spec buffer tube castle nut
• Receiver endplate