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 barrel nut does not line up to install gas tube
southshoreangler  [Team Member]
5/10/2008 4:31:04 PM EST
I recently bought an ar with a loose barrel.
I thought all I would need to do is tighten it up but I see now why it is loose. if I torque teh barrel to 80lbs the nut does not align with the gas tube. Are there shims or something for this?
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briansmithwins  [Team Member]
5/10/2008 4:35:35 PM EST
Tighten the barrel nut until a notch is aligned. There aren't any shims you just have to crank it. That said, tightening and backing off in succession can get you lined up without over torquing. BSW
southshoreangler  [Team Member]
5/10/2008 4:37:07 PM EST
Thanks I am already at 80 lbs how much torque can i get away with?
MrMaeda  [Team Member]
5/10/2008 4:38:12 PM EST

Originally Posted By southshoreangler:
Thanks I am already at 80 lbs how much torque can i get away with?


Dont, just back down one notch so that the gas tube can fit through it and the receiver.
southshoreangler  [Team Member]
5/10/2008 4:39:04 PM EST
if i back it off to 30 lbs it aligns will this do?
BigBore45  [Team Member]
5/10/2008 4:43:44 PM EST

Originally Posted By southshoreangler:
if i back it off to 30 lbs it aligns will this do?


Back it off and re torque at 60. If your still shy just go to next notch.
flatop_a3  [Team Member]
5/10/2008 4:46:07 PM EST
just back it off one notch and put the gas tube in, no need for shims.
inkaybee  [Member]
5/10/2008 4:48:11 PM EST
ar15bharrels.com used to sell shims but I think he is out of the business. I have used them and they work like a charm.
KDavis  [Member]
5/10/2008 5:05:28 PM EST
It is bad practice to back the nut off to line up a notch, just better to set the torque in the direction of tightening.

On the couple of guns I have built, I tighten to 30ft/lbs, three times (torque, loosen, torque, loosen...) -- then I take the nut to 40ft/lbs and if needed, tighten to line up the next notch.
Jimmy_Hoffa  [Member]
5/10/2008 5:18:01 PM EST
A LOT of people have used this method: hand tighten, then use a wrench to tighten UNTILL the gas tube can go in. I had to swap 2 barrels yesterday & today and couldn't find my torque wrench and used that method. Worked great. Found torque wrench laying in a pile of trash under my work bench later.
JoshAR  [Team Member]
5/10/2008 5:43:02 PM EST
I believe it's torque to 60 3 times then the next hole but what do I know.

In line with this, I wouldn't push it past 80.

ar15.com/forums/topic.html?b=3&f=4&t=315921
Otterstedt  [Member]
5/11/2008 4:01:27 AM EST
The 23&P says to torque three times to 30lbs, then torque further if needed to align, but do not exceed 80lbs. Refer to pages 3-41 through 3-43.
QUIB  [Team Member]
5/11/2008 4:37:30 AM EST
Don't forget the grease!
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