Under torqued barrel nut

Carr1ck

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I installed a new barrel with odin works o2 lite hand guard on my stag 10 and can not get the gas tube in when torqued to the recommended 50 ft pounds. It seems the alignment pin is to small or the gas rod hole is to big, it shifts enough when torqued that I cant get the gas tube in unless I back the barrel nut off a bit. So I have no idea of the torque value, its covered in vibra tite and I went ahead and finished the build. Any suggestions? Safe to test to see if accuracy is acceptable before messing with it more?
 
I installed a new barrel with odin works o2 lite hand guard on my stag 10 and can not get the gas tube in when torqued to the recommended 50 ft pounds. It seems the alignment pin is to small or the gas rod hole is to big, it shifts enough when torqued that I cant get the gas tube in unless I back the barrel nut off a bit. So I have no idea of the torque value, its covered in vibra tite and I went ahead and finished the build. Any suggestions? Safe to test to see if accuracy is acceptable before messing with it more?

There should be a Min/Max for any AR style barrel nut.
You need to get the gas tube hole to line up with the nut keys within that spec.
It's pretty rare it doesn't.
But in the event that whatever combination of parts you're using results in this unlucky scenario, they sell a barrel nut shim you will slip over the receiver threads and then attempt to torque into those ranges again.

Find the min/max standard for AR10 nuts.

Torque the nut to the min immediately. Actually the C7 armourer manual procedure says to set to min torque then tighten and back the nut off 3 times to the minimum torque spec of 30 ft lbs for the C7 (30 min and 80 max for Colt made C7 Rifles) Then set your wrench to the max and start torqueing until the next key lines up properly. If your wrench tops out at the max and it still hasn't lined up then you will need a shim.

Once torqued to min you should never back the nut off to align a key. Only torque up until you align it and stop.

Bare in mind it's your receiver brand that you need the min max ft lbs for NOT your barrel nut. Depending on what they're made of the manufacturer may recommend lower max torque values if it's cheap air filled junk....NEA cough *cough lol
 
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You have to take your time and go slow. If you don't know the torque don't shoot it. Loosen and re torque. It can be from 30-80 ft lbs. Try 30 and check tub, then 40 then 50 all the way up to 80. Somewhere it should line up. If not then loosen off and try again. 30-80 in steps. Keep going until it lines up. If it will not line up at all then barrel shims will help.
 
The way that particular nut goes on it is just a matter of keeping the one half of the barrel nut with the gas tube hole lined up with the reciever gas tube hole and tightening the other half of the nut to the desired torque.
There is a pin that it comes with that you use temporarily to keep the upper reciever gas tube hole lined up with the one half of the barrel nut with the gas tube hole. You tighten the other half of the barrel nut up to the first with that pin in place to keep the holes lined up.
You can try a small shim on the side you are tightening to and try to hold onto the upper reciever so it doesn't shift too far over when you torque it. I was able to hold my upper the opposite direction of torque enough that all of mine have lined up perfectly after having the same issue you described. Have done that same method (just holding/twisting the upper the opposite direction) now on 3 O2 lite handguards.
If it is off a bit you can usually wiggle the gas tube in there.
I found it not too bad with a barrel extension wrench, keeps some of the torque off the reciever. But it might be harder to accomplish with a upper reciever jig or other methods that hold the upper and not the barrel extension.
 
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That video suggests 80 lbs
I believe Odin suggests 40-50.
I would imagine anything between 40 and 60 is ideal. 80 seems like a bit much.
Odin suggests the same torque on the AR-15 and their AR-10/308 versions.
If I recall the directions and torque specs are on the box.
I believe the wrench sizes are different on the 308 (1&3/8) vs the AR-15 (1&1/4), as I found out when my 308 version arrived.
 
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The way that particular nut goes on it is just a matter of keeping the one half of the barrel nut with the gas tube hole lined up with the reciever gas tube hole and tightening the other half of the nut to the desired torque.
There is a pin that it comes with that you use temporarily to keep the upper reciever gas tube hole lined up with the one half of the barrel nut with the gas tube hole. You tighten the other half of the barrel nut up to the first with that pin in place to keep the holes lined up.
You can try a small shim on the side you are tightening to and try to hold onto the upper reciever so it doesn't shift too far over when you torque it. I was able to hold my upper the opposite direction of torque enough that all of mine have lined up perfectly after having the same issue you described. Have done that same method (just holding/twisting the upper the opposite direction) now on 3 O2 lite handguards.
If it is off a bit you can usually wiggle the gas tube in there.
I found it not too bad with a barrel extension wrench, keeps some of the torque off the reciever. But it might be harder to accomplish with a upper reciever jig or other methods that hold the upper and not the barrel extension.

Thanks, how do you keep the nut with the gas rod hole in it in place while torquing the other nut? What kind of shim did you use? I cant hold it with my hand. I’ll take it apart and try again. Do you use the vibra tite? Did you clean it off after you ran into problems?
 
I have never done a ar10 .. but I would imagine anything between 40 and 55

If you have to go over 55 I would use a shim .... Have used a Pepi Can and some small/ sharp scissors

and if you use a shim and do not like it you can take it out, and try a different way

I think if you have to go to 80 you would bend some thing. or rip threads out .... its only rated to 60-70 tensile
 
Took everything back apart used two hands to gorilla hold the forend adapter while the wife torqued and got it to the odin works 50 ft pound recommendation and the gas rod slid in. Took one shot with the adjustable gas block on zero and it went boom and not kaboom so Im happy. Will sight it in Sunday. Everything looked good, case looked fine, however, it was super hard to eject the round with the charging handle. Is that something to be concerned about?
LZK6Emp.jpg
 
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That video suggests 80 lbs
I believe Odin suggests 40-50.
I would imagine anything between 40 and 60 is ideal. 80 seems like a bit much.
Odin suggests the same torque on the AR-15 and their AR-10/308 versions.
If I recall the directions and torque specs are on the box.
I believe the wrench sizes are different on the 308 (1&3/8) vs the AR-15 (1&1/4), as I found out when my 308 version arrived.

There are very few upper receivers by brand I would trust to torque to 80 ft lbs
Thats the wheel nut torque of your average 4 door sedan car.
The actual military C7 rifle 1st line repair manual has 80ft lbs as the upper limit for a Colt Diemaco Upper. Even then....
 
Thanks, how do you keep the nut with the gas rod hole in it in place while torquing the other nut? What kind of shim did you use? I cant hold it with my hand. I’ll take it apart and try again. Do you use the vibra tite? Did you clean it off after you ran into problems?

I actually just swapped handguards last night and used a small strap wrench to hold the first nut in place while I torqued the second outer barrel nut. This was with a barrel extension wrench. Was easier to hold in place with the strap wrench then by hand. I just tried to put enough pressure on the strap wrench that it didn't jam all the torque against the supplied gas port pin.
I use Aeroshell grease, not the supplied vibra-tite as I change things around here and there.

I am glad you got yours sorted also.
And yes Travis, as I mentioned previously, 80 lb ft is pretty excessive. 40-60 lbs seems reasonable.
 
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