Choosing Your AR-15 Buffer Tube

bitgod

I recently acquired a CAA CBS Collapsible Butt Stock for my Colt Sporter Match HBAR .223 AR-15. I didn't realize at the time the fixed stock buffer tube would not work with the collapsible stock. How do I choose the buffer tube that will be compatible with my new butt stock, and will the buffer and spring need to change as well? Thanks in advance for any advice.

dcs shooters

You need the tube-buffer-spring for a carbine.

Nwcid

There is not much difference between tubes. There is 2 different sizes of tubes, Mil Spec and Commercial, most being commercial. The Mil Spec is just slightly smaller so unless your stock happens to be Mil Spec either will work.

You will need a Carbine buffer and spring to use as well.

Txs

I believe CAA makes both commercial and milspec buttstocks. Either measure the inside diameter of the one you have to see which tube would fit correctly or contact the manufacturer and give them the model number. While it's true that a commercial buttstock will fit on a milspec tube, it's going to have noticeable looseness, will rattle and possibly have problems with positive lock-up.



After determining which one you need, there's a simple way to tell if one you're looking at is commercial or milspec. Commercial tubes have the receiver threads cut into them, with the overall diameter of the threads the same as the tube diameter. The threaded area on milspec models is actually larger in diameter than the rest of the tube.

Commercial Left/Milspec Right