Originally Posted by musclegto
I shoulda have been more clear. I meant to ask if I need to buy a buffer tube, or if the magpul ctr will fit on the buffer tube that comes with the rifle.
Generally speaking, they're all the same as far as brands go, but there are two sizes. Mil-spec measures 1.148" in diameter and commercial spec measures 1.168" in diameter. There's no benefit of one over the other, so just make sure you buy the stock for which ever tube you have.