Need help installing a barrel nut on an AR 15

[JasonK007]

I know there are many threads about the torque pounds on a barrel nut. But I didn’t see anything that specifically answers my question.

I was checking a few things on my new Huldra Arms 5.45 piston AR last night and had removed the barrel nut with my AR tool. I had instantly noticed it was very difficult to remove. When I went to reinstall it to the 35-80 pound range, the holes would not align properly in order to get the piston through. Based on my torque wrench readings, the one hole through the barrel nut aligns at 25lbs, and the very next hole requires 100lbs. Both of these numbers put me out of the recommended range.

Does anybody have suggestions as to where to go from here to get within range?

[cdi]

Torque it to the bottom of the recommended range, then as much as needed to line up the gas tube- even if it exceeds 80 lbs.

[elementfreak431]

Try putting some grease on the threads. That should help

[JasonK007]

Try putting some grease on the threads. That should help

I tried this. I was able to get down to 95lbs. But that's still 15 over the limit. My weapon was shooting several inches off at 50 yards, and I believe it's because of the nut being over-torqued from the factory.

[Lycanthrope]

When you do it right you just don't tighten to the next value.

You back it off, tighten back it off, tighten......etc......until you work the threads to the next hole. It will then typically fall between 30-80ft/lbs.


Lycansighthrope

[JasonK007]

I just spent the past several hours messing with this barrel nut. I tried lots of grease. And I tried tightening the nut, loosening, tightening, around 15-20 times with almost no luck at all. I know some nuts are aluminum; mine is not. I'm wondering if the harder alloy is having something to do with it. I’m currently at 15 pounds of torque with the one hole and 95 pounds with the very next hole. Based on some further digging elsewhere, I have a few options.

1. Buy a lapping tool with compound
2. Find or make shims
3. Buy a new barrel nut (and hope the new one is better)
4. Leave the torque at 95lbs
5. I have no idea

[o1dakota440]

could your torque wrench be out of spec?

[Lycanthrope]

I'd leave it at 95lbs. The danger of going over is in ripping out the threads and damaging the receiver.

Weird things happen to accuracy when you overtorque the muzzle devices, but at the barrel nut I can't see where that would be an issue.

What do you mean by shooting several inches off? It's not uncommon to have to zero a rifle......or to have to rezero it with varying ammunition. Are you nearly out of adjustment in the rear sight? (sometimes that can be a canted front sight tower)


Lycansolvetheoriginalproblemthrope

[JasonK007]

I'd leave it at 95lbs. The danger of going over is in ripping out the threads and damaging the receiver.

Weird things happen to accuracy when you overtorque the muzzle devices, but at the barrel nut I can't see where that would be an issue.

What do you mean by shooting several inches off? It's not uncommon to have to zero a rifle......or to have to rezero it with varying ammunition. Are you nearly out of adjustment in the rear sight? (sometimes that can be a canted front sight tower)


Lycansolvetheoriginalproblemthrope

Basically, my rifle was shooting around 6 inches to the right at 50 yards. I was able to adjust my rear sight to compensate for that. But I feel like that’s putting a band aide on a gunshot wound, meaning the underlying problem isn’t going to be solved. Therefore, I went on a witch hunt to determine the problem.

The first thing I checked was the cant of my gas block. It didn’t appear to be off, but it is hard to tell without a tool. Regardless, the gas block is pinned through grooves on the bottom of the barrel. And therefore moving it in one direction or the other would be almost impossible.

After doing a little digging, I was able to find information that if the barrel nut is over-torqued, the gun won’t shoot straight. It also is supposed to cause additional stress on the receiver. This is why I’m trying to get the lbs into the recommended range. I think I’m going to end up going into my local AR shop and see if he sells barrel nuts. I’ve read that they are not all equal, meaning some fit and some don’t.

Thanks everybody for your responses. I’ll update once the problem is solved.

[Lycanthrope]

I don't think that would cause what you're seeing. I wager the gas block is out of index a bit with the receiver. There are ways to fix that by reindexing the barrel at the receiver.

Does your barrel fit tightly into the receiver channel is there now a lot of side to side play?

Lycannextstepsthrope