barrel nut torque

[ybrik]

I just swapped out a 16.1" to 14.5" barrel.
Now, when I set the torque wrench to 30 ft-lb., it clicked and after checking, the gas tube aligned with the barrel nut and upper receiver.
Is this good enough? barrel secured with upper?

From other assembly vids I saw, after setting the wrench to 30, set it to 40 then go to next nut indentation. But in my case, I didn't have to go to 40 ft-lb.

I was just thinking that since my upper had a previous barrel installed before, I used a new nut with the 14.5" barrel. Then I torqued to 30, then loosen, then torque to 30 again and as far as I know I gave an extra torque maybe 1 ~ 2 ft-lb more when the wrench had clicked. But this time I just wanted to check the gas tube hole and it is aligned and was able to pass the tube smoothly.

Am I really good to go?

[MistWolf]

Yes, 30 ft/lbs is good to go

[ybrik]

okay then, will completely assembly the gas and FSB.
thanks.

[ybrik]

I loosened it up and re torqued. Here is the notch position at 30 ft-lb.
I haven't tried setting the wrench at 40 and attempt to align as the wood top where the 5" vise is bolted was starting to flex.
I'm not sure if this will be over 40ft-lb to align the gas tube on the next notch.

[Ryno12]

I believe the spec is 30-80#. Personally, I'd tighten it to the next notch & call it good.

You can also try a different barrel nut. They're cheap.

[hk_shootr]

Lube the nut and the face of the barrel with moly then torque to 30 ft lbs & loosen three times.
If it is not aligned on the third, turn to the next position.

[ybrik]

There is moly grease in there. I've tried more than 5x torque to 30ft lb then loosen.
I'll try it to next notch set at 40 and have a buddy hold/support the vise just in case it flexes the table more.

Hope it will be good as this is my first time and really not looking to have issues with the threads.

[Jwknutson17]

I torque all of mine to 50. Never had an issue. Between the 30-80 spec, I would be hesitant to be on the light side. But then again. Lots of folks run on the light side 30 ish with no issues. 40 should be GTG, but you might be all the way on the higher end of spec to get it to the next notch. When its tight, hardly any movement in the nut increase the torque by a lot.

[MistWolf]

I loosened it up and re torqued. Here is the notch position at 30 ft-lb.
I haven't tried setting the wrench at 40 and attempt to align as the wood top where the 5" vise is bolted was starting to flex.
I'm not sure if this will be over 40ft-lb to align the gas tube on the next notch.

Set the TW to 80 ft/lbs and keep turning the barrel nut until the notch lines up. If the TW reaches 80 before then, take a look and see how close it is. If it's real close, go ahead & turn it till it does. A little more torque won't hurt anything. If it's off by a bit more than a little, loosen the nut & torque it to 80 ft/lbs a few times and see if it comes in closer. Torque slow and steady to keep from damaging the threads. The biggest problem with over-torquing is that it can cause the threads to fail and aluminum threads are very unforgiving in this respect. Ryno is right, however. If you just go to the next notch, you should be good

[ybrik]

I'm using a dpms wrench. I'll try to use this time the webbings on the wrench instead of the 2 index posts.