View Full Version : 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/j116/mos21112/IMAG0513.jpg
http://i78.photobucket.com/albums/j116/mos21112/IMAG0512.jpg
http://i78.photobucket.com/albums/j116/mos21112/IMAG0511.jpg
http://i78.photobucket.com/albums/j116/mos21112/IMAG0514.jpg
An Undocumented Worker
08-18-11, 17:52
It appears as though the barrel wasn't drilled for the pin that goes into the barrel extension.
Are there any marks, or holes in threads in the barrel where that pin in the extension would have sat in the barrel?
It appears as though the barrel wasn't drilled for the pin that goes into the barrel extension.
Are there any marks, or holes in threads in the barrel where that pin in the extension would have sat in the barrel?
my shitpad crashed. the barrel is not drilled for the pin, and you can see in the last picture that the pin is recessed inside the receiver extension and wouldnt be long enough to touch the threads. So, I guess thats several different kinds of fail.
nice huh?
The barrel extension wasn't tightened properly. The alinement pin doesn't play much of a factor in keeping the extension in place. The pin doesn't go into the barrel steel given that it is 0.185" - 0.005" long and sits flush into a ~0.34" diameter. Torque on the extension is 150 ft/lb +/- 5 ft/lb
I saw it happen once on an Oly arms barrel.
Looks cool
http://www.primeaffiliate.com/track/images/18.games.jpg
The barrel extension wasn't tightened properly. The alinement pin doesn't play much of a factor in keeping the extension in place. The pin doesn't go into the barrel steel given that it is 0.185" - 0.005" long and sits flush into a ~0.34" diameter. Torque on the extension is 150 ft/lb +/- 5 ft/lb
I've wondered why barrel extensions aren't staked or something.
Receiver extension end plates MUST be staked. Gas keys MUST be staked.
FSB/gas block MUST be pinned.
Barrel extensions get a pass?
Is it just the relatively high torque that keeps these in place and makes loose ones a rare occurence?
The only way that this could happen is that the barrel extension was not tightened or torqued to the barrel properly.
Looks cool
http://www.primeaffiliate.com/track/images/18.games.jpg
What is this bullshit?
That's a first for me as well. I agree that it wasn't properly torqued to begin with.
Receiver extension end plates MUST be staked. Gas keys MUST be staked.
FSB/gas block MUST be pinned.
The collapsible stock lock ring didn't used to be staked, that came along with the M4 lock ring. Gas key staking is to retain the heads of the cap screws if they fail. FSBs were pinned at the start but that's not a MUST just one of the most secure (and grunt proof) methods. 150 ft/lb is a lot. Seen many bolt guns with staked barrels? :D
Crazy, I have never had that happen, nor have I seen it happen.
Yea I've never seen one come off or read about it.
Very interesting. Please post the mfg with an update on what they do for you.
I saw it happen once on an Oly arms barrel.
That makes sense. But on real ARs... I've never heard of such a thing.
It appears as though the barrel wasn't drilled for the pin that goes into the barrel extension.
Are there any marks, or holes in threads in the barrel where that pin in the extension would have sat in the barrel?
The index pin does NOT have any contact with the threads on the barrel. Torque is all that is need to secure the barrel extension.
You should never fixture the barrel in a vice as a means to hold the upper receiver group when removing or installing a barrel assembly. Doing so will almost inevitably cause either the index pin to be sheared off during removal or the barrel extension getting loosened during installation.
I wonder what brand AR it is?:nono:
The company is already "fixing" the issue, and it goes off in the mail Monday. The barrel was a first run of DSA's 175$ barrels or 300$ uppers. This was bought over a year and a half ago or longer and had a life cycle of 1500 rounds. I guess you could say this failed right at the time one would consider the "break in" complete. I always try to put about 1k through a gun before assurance in performance.
I thought this thread had some value and others might benifit from its contents.
That makes sense. But on real ARs... I've never heard of such a thing.
Your right I never seen it on a real AR barrel.:D
real ARs.:haha:
hater :dirol:
That makes sense. But on real ARs... I've never heard of such a thing.
Happened to me with an M16A2. Real enough for ya?
Happened to me with an M16A2. Real enough for ya?
Background?
Nobody_Special
08-22-11, 08:28
Same thing happened to my friend's DSA upper.
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Happened to me with an M16A2. Real enough for ya?
Teachable Moment: this is just WAY too blatant, especially since from out of freaking NOWHERE.
If you think that somebody's experiences being simply different from your own is cause for your :internettoughguy: BS, think again.
Whether or not your instance involves a "real" gun or not, the member you directed that toward simply not having had it occur is not the same as him slapping your mother at the dinner table, regardless of any potential increased molarity of urine in your morning muesli.
As for this cat's background, it's gonna be "infracted" if he can't reel his crank back in.
Same thing happened to my friend's DSA upper.
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- Sent from my brain using Tapatalk
This is starting to sound like a classic case of "if it sounds too good to be true..."
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