AR buffer tube question.

[jkgts1]

Okay, I built a AR last year with a commercial tube and commercial Magpul MOE butt stock. With that combo my stock wiggles, I figure no big deal, it still works. Well now its bugging me, I contacted Magpul to see if play was normal, gentleman said yes a little play is normal. Okay so I figured I would get a Magpul CTR stock instead, because it has a friction lock. Well I put it on and it still has play, but not as much as the MOE did. I measured the buffer tube with calipers and it has the Mil spec diameter, WHAT! So, is it safe to say I have a mil spec? My buffer tube is flat with no angle, but has 6 positions of adjustment. I checked my original buffer tube order and it does say commercial. My brother in law has a CTR mil spec on his AR and his doesn't even have play. You guys think I just got a mil spec by mistake? Would it be a safe bet to exchange the CTR commercial for a CTR mil spec?

[tanakasan]

Calipers don't lie!

Sounds like a mislabeled tube on the first go around. My MilSpec CTR and STR lock up solid.

Robert

[steve92407]

mil is1.148 comm is1.168" od

[jkgts1]

yeah mine measured at 1.145.

[stevie]

Sounds like you may have a mil-spec tube. Ask for an exchange or order the correct tube and start another build.

[digdug74]

Sounds like it's probably a mil-spec tube. Check the threads, too. That's another area where mil-spec differs from commercial. If the threads are larger in diameter than the body of the tube, it's likely mil-spec. If they are the same diameter, it's likely commercial.

[missiontrails]

Get a mil spec CTR, and it will lock tight as a mofo.