strange problem with my M-4...

[M-4 shooter]

Well I've got a M-4, that I bought brand new and.. The barrel shot loose! It was so loose that I unskrewed it with my fingers, what in the world would cause that to happen? It grouped real tight and then after 250 rounds the groups just well, it didn't have groups after that, more like spreads. I got a torque wrench and torqued it to about 35 LBs, what is the liklyhood that its going to happen again?? Ideas? Suggestions? (maybe an explanation as to how it happened)?

[DEPUTY]

first off who made the gun? or is it a kit gun that was put together

[M-4 shooter]

It's a bushmaster A4 upper with a wilson combat bull barrel that my brother put together, everything was new and he SAID he torqued it at 33 LBs. with good ammunition it would get one hole groups at 70 yards, but now I don't have any confidence in the weapon. I dont understand how the barrel nut got loose because the gas tube goes through the barrel nut, so it could not get loose without twisting the gas tube right? And the gas tube was not twisted.

[KN]

I had the same problem with a DPMS heavy upper that I put together. Every thing was tight but after a couple hundred rounds the accuracy just wasnt there. Picked it up out of the safe by the barrel and felt it turn. I ended up taking it apart and when it went back together it was one hole farther tight than it was originally. Don't know why, cant explain it. Hasn't come loose yet after another 300 rounds or so and my accuracy is back.   KN

[wgates011]

I like to touque mine 3 times.. i read that on ar15.com.. there pretty smaret over there.. they really know thier ar15s.

[S.S.]

Welcome to the world of M-16/AR clones.
Strange things happen to them pretty regularly
and at most inopportune times !
You could not chase me fast enough to give me one!

[jason280]

Funny, I've never had that problem before. In all liklihood, the builder was the problem and the rifle wasn't assembled correctly.  I've owned close to ten or more AR variants, and put several thousand rounds through them over the years with not a single barrel nut coming loose.  If they are spec'd correctly, this should not be a problem.

Also, like its mentioned above, check out AR15.com!

[allenr]

Funny, I've never had that problem before. In all liklihood, the builder was the problem and the rifle wasn't assembled correctly.  I've owned close to ten or more AR variants, and put several thousand rounds through them over the years with not a single barrel nut coming loose.  If they are spec'd correctly, this should not be a problem.

Also, like its mentioned above, check out AR15.com!

Same here,  I currently have 3 ar rifles and 1 ar pistol. I built them all myself. Have never had a prolem. Most accurate and reliable firearms I have ever owned.

[mt3030]

....You could not chase me fast enough to give me one!

Good! Glad to hear it! Then I know you will not have just purchased the one I was looking for. I only have 5, and I'm always looking for the next!
Besides, it is obvious from your statement that you have no experience with them, and all men should know their limitations. (Here's your sign!)