View Full Version : barrel nut torque
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?
Yes, 30 ft/lbs is good to go
okay then, will completely assembly the gas and FSB.
thanks.
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.
http://i6.photobucket.com/albums/y214/ybrik_5/barrelnut__zpsf0d29475.jpg (http://s6.photobucket.com/user/ybrik_5/media/barrelnut__zpsf0d29475.jpg.html)
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.
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.
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
08-11-14, 12:12
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.
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.
http://i6.photobucket.com/albums/y214/ybrik_5/barrelnut__zpsf0d29475.jpg (http://s6.photobucket.com/user/ybrik_5/media/barrelnut__zpsf0d29475.jpg.html)
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
I'm using a dpms wrench. I'll try to use this time the webbings on the wrench instead of the 2 index posts.
556BlackRifle
08-11-14, 13:49
Properly lube with AS33MS and torque to 40 loosen and tighten three times. I shoot for 45 to 50 for the final torque more if required for alignment.
Also, get yourself a Reaction Rod. :)
Ya can't to the job properly if the vise is not securely mounted.
Remount the vise or find another.
Ya can't to the job properly if the vise is not securely mounted.
Remount the vise or find another.
I hate to pile on but.... If the setup is coming apart at 30 ft lb you need another setup. While I am at it.. Am I the only one that turns the nut wrench 90 degrees to the torque wrench for accurate readings??
I'll find another platform to bolt the 25lb vise.
I install the TW inline with the nut wrench which is same as in the tech manuals.
I hate to pile on but.... If the setup is coming apart at 30 ft lb you need another setup. While I am at it.. Am I the only one that turns the nut wrench 90 degrees to the torque wrench for accurate readings??
As long as the adapter is not over 2" from the center to center, this is the best option
Great point to gab ring up. If an adapter is used, and installed inline from the torque wrench, the applied torque will be greater than where the torque wrench is set.
Here is a good chart that has the calculation tables for torque adapters
https://www.motorcraftservice.com/renderers/torquewrench/wrench_formula_main_en.asp
Update:
I tried to align on the next notch. This is where it is, TW set @ 50 ft-lb (actual torque of 54ft-lb using torque adapter calculations from the above).
http://i6.photobucket.com/albums/y214/ybrik_5/nut_at_50ftlb__zps15ebd4ec.jpg (http://s6.photobucket.com/user/ybrik_5/media/nut_at_50ftlb__zps15ebd4ec.jpg.html)
The notch just moved very little from 40 ~ 50.
Will I start to get issues above 50 ft-lb?
Will I go over the 80 ft-lb limit to align this nut?
Since my bench is flexing, I have a 10" x 36" concrete foot step laying around to use as vise platform.
It has 1.5" thickness and I'm thinking to bolt the vise there. Sure thing there won't be any flexing beyond 50 ft-lb of torque.
Just came across bison Armory shim sets. Would that be a good idea to so I would get to align the notch around 40~55 ft-lb range?
Am I the only one that turns the nut wrench 90 degrees to the torque wrench for accurate readings??
If you're turning the torque adapter 90 degrees or if your compensating for the extra length, you are doing it wrong. The manual states that the proper torque is 30-80 ft/lbs with the barrel nut wrench
...Will I go over the 80 ft-lb limit to align this nut?
Just line it up and press on! The barrel nut is set up that it will usually line up within the proper torque range even without using a torque wrench. There are a vast number of ARs that have been built without a torque wrench and they all run fine. Quit agonizing over this and finish installing your barrel
BufordTJustice
08-12-14, 05:34
Just line it up and press on! The barrel nut is set up that it will usually line up within the proper torque range even without using a torque wrench. There are a vast number of ARs that have been built without a torque wrench and they all run fine. Quit agonizing over this and finish installing your barrel
Agreed. Just use PLENTY of grease on the threads and rock on.
If you're turning the torque adapter 90 degrees or if your compensating for the extra length, you are doing it wrong. The manual states that the proper torque is 30-80 ft/lbs with the barrel nut wrench
That's right. To be clear, it's with a specific barrel nut wrench in the extended position (not rotated 90 degrees), and it gives you exactly 2 inches of extension measuring center to center (barrel nut center to torque wrench center).
Joe Mamma
There is waaaaaaay too much thinking going on here. First things first.
1. Mount the vise correctly.
2. Remove the padded vise jaws, they aren't needed.
3. Set the wrench to 30 ft./lbs. After you hit it, use a breaker bar and apply steady pressure until you hit the next notch.
Okay I have completed it earlier.
Bolted the vise on a 2" thick concrete foot step.
Then I torqued to 30 ft-lb. I reached 80 and still it's gas tube notch not yet aligned. So I torqued to 80 (and at one point 90) then loosened and did it like 6x.
Until then the notches aligned at 83 ft-lb. I hope this is good as I have no plans of doing the shims or lapping the upper as work around.
I just hope that this is still accurate. btw, the aeroshell really did it's job when I reached 90 ft-lb at one point.
If I were using any barrel nut that required alignment for a gas tube notch I'd just get an ALG shim set from Grant and find a combo for 30# and be done with it.
Good grief! Do as Iraqgunz said and move on.
Range report earlier today:
Had 100 x Norinco 5.56x45mm surplus ammo
One of the target papers, rifle's front-end supported.
http://i6.photobucket.com/albums/y214/ybrik_5/25yd_6920_145_socom_barrel_zps0e3b3c00.jpg (http://s6.photobucket.com/user/ybrik_5/media/25yd_6920_145_socom_barrel_zps0e3b3c00.jpg.html)
My shots are always below the center even when using pistols.
I guess the 83 ft-lb. barrel nut torque wasn't that bad.
Sights are made to be adjusted such that your shots are not "always low"
Rick
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