This Buffer Tube Assembly from Doublestar is built to mil-spec dimensions in the carbine style for the AR-15. The buffer tube (receiver extension) houses the recoil buffer and spring and provides the mounting point for a collapsible stock; mil-spec tubes are sized slightly smaller in diameter than commercial-spec tubes, so stock compatibility depends on matching the spec (Doublestar part no. AR355M).

Key Specifications

• Functions as the buffer tube (receiver extension), housing the buffer and spring and mounting the stock.
• Built to mil-spec diameter, matching mil-spec-pattern collapsible stocks.
• Configured in the carbine length rather than a rifle-length fixed tube.
• Sold as a complete assembly, ready to thread onto the receiver.
• Provides the mounting point for a collapsible stock.

Frequently Asked Questions

What does the buffer tube do? It houses the recoil buffer and spring and provides the mounting point for a collapsible stock.

What’s the difference between mil-spec and commercial buffer tubes? Mil-spec tubes are sized slightly smaller in diameter, so stock compatibility depends on matching the spec of your stock.

Buy the Mil-Spec Carbine Buffer Tube Assembly

Complete your AR-15 build with this mil-spec carbine buffer tube assembly from Doublestar. It ships fast from our Lubbock, Texas gun shop, and our rifle parts selection has more rifle parts.