Stock actually fits it tight - Guntec USA AR-15 Mil-Spec Buffer Tube

Bought to mount on a cheap 12ga. Also bought a Hogue stock and pistol grip, but since that package is coming a couple days later, I went ahead and installed and mounted up a cheap factory stock that came of an M&P Sport. The one thing that blew my mind was that it was a snug fit and didn't rattle around any. Factory stock on both my S&W and Sig AR's rattled like crazy and were replaced by Magpuls with the locking lever. I almost want to swap the tube to one of those other guns rather than keep it on a cheap Mossberg.