Have you ever had your barrel come loose?
I have already contacted the mfg and it will be returned to them for free and either fixed or replaced (replaced...).
I was at the range with my trunk gun that has about 1,500 rnds down the pipe all commercial or xm193. I was shooting at 200 yds and noticed I was patterning strange when I checked the target. As I got a sight picture upon retrun I noticed my fsb appeared canted. I stopped to check my free float rail, aimpoint and aimpoint mount and all were steady. I grasped the fsb and to my surprise the barrel rotated until it was stopped by the gas tube. I came home and called the mfg and then un pinned the fsb, pulled the ff rail and snapped some pics. The collar and barrel had become loose and I was able to unscrew the collar with my fingers from the barrel . After cleaning it all up, the collar is intact, as it the barrel and my upper. I also noticed no thread locker traces or staking or anything else. I have had no popped primers, ejector marks on brass or case head separations, ect. on my brass, nor have any round felt or sounded "off."
So this experience leaves me with two questions.
1. What is the "industry standard" for torque or thread locking on a barrel and collar?
2. Has anyone ever seen this happen before (6yrs as a 3rd level 2111 and I never saw this, most uppers would deform or some other component would break if force were applied to the fsb)
http://i78.photobucket.com/albums/j1...2/IMAG0513.jpg
http://i78.photobucket.com/albums/j1...2/IMAG0512.jpg
http://i78.photobucket.com/albums/j1...2/IMAG0511.jpg
http://i78.photobucket.com/albums/j1...2/IMAG0514.jpg