Broken Barrel Nut

[ZKMC18]

To start off with, I’m very new to assembling my own ARs as This thread will show.

I tried to set an 8” 300 blackout barrel into the enhanced Aero Precision Upper.

I used a Geisele(sp) reaction rod in my vice with Aero Precision’s barrel nut and wrench with my own, way oversized for the job torque wrench.

Long story short, Aero Precision recommends 50-55 footpounds of Torque. I think I was able to manage 35-40 pounds of torque before the wrench warped and broke basically every tooth off the barrel nut. I ordered a new wrenched and tried my best to remove the barrel nut, but it’s basically impossible. The barrel is in there SOLID.

My question is... am I completely out of luck and should scrap the upper or will I able be able to safely fire the upper, and just be out of luck in a year or so if I wanted to change out the barrel?

Thanks.

[MegademiC]

pic of wrench? I dont even know how thats possible.

I would try to remove the nut, maybe weld or jb weld a cheap wrench to it.
Or just assemble it and see how it works, id imagine it will be fine, assuming you didnt cross thread it or anything like that.

I still dont understand how teeth broke off.

[AKDoug]

Pic of the whole thing? What barrel nut?

[ZKMC18]

Pictures to follow this evening.

So when I say “wrench” I mean the wrench attachment that has grooves to fit the barrel nut.

https://aeroprecisionusa.com/m4e1-ba...ut-wrench.html

According to Aero Precision, this is a pretty common problem and it’s difficult to keep the torque wrench perfectly perpendicular.

The barrel nut is this one, with all teeth broken off.

https://aeroprecisionusa.com/cop-barrel-nut.html

[GH41]

A picture would help but it sounds like you've got a mess. Before I threw it away I would try a couple of things. First I would try to get it loose with a hammer and punch. Not a heavy hammer, Maybe 10-12 oz. The effect is like an impact wrench. Another way would be get a piece of steel tubing maybe 1/8 wall (NOT PLUMBING PIPE) Large enough to slip over the barrel and have the best welder you know TIG it to as much of the nut as he can see. Think of like an extra long deep well socket.

[26 Inf]

A couple of things I would try before I went to welding, etc.

As I understand a couple of teeth are left. Are any threads from the barrel nut visible? If you have enough surface simply use a pipe wrench to remove the barrel nut.

Since it is 'stuck' I would try to use barrel blocks first in order to ensure I didn't unseat the barrel extension. Otherwise, make sure your reaction rod is solidly secured.

You can make a set of barrel blocks easily enough -

* get two short lengths of 2x4, mate them perfectly together tighten them into your vise (alternatively you could screw them together);

* use a speedbore type ( http://www.irwin.com/tools/drill-bit...speed-bit-sets ) as close to your barrel diameter as possible and dril through the 2x4's at the joint - the speedbore screw end gets you started and holds in place until the larger cutting bit engages the wood;

Attachment 52409

You say there are a couple of teeth left on the barrel nut. If the pipe wrench won't work, drive the nut off. The receiver has to be solidly mounted for this, so I would probably use the reaction rod to reduce vibration.

If you have a piece of hardwood, I would use it against the tooth, otherwise use a large machinist punch. Make sure it is solidly mounted and that the punch/board is solidly against the tooth. Use a big enough hammer to transfer some energy and sharply rap - versus pound/beat - looking for an impact that jars with as little force as possible. You can increase the power of your blows as needed, but start with a sharp rap.

You'll get it.

[GH41]

A couple of things I would try before I went to welding, etc.

As I understand a couple of teeth are left. Are any threads from the barrel nut visible? If you have enough surface simply use a pipe wrench to remove the barrel nut.

Since it is 'stuck' I would try to use barrel blocks first in order to ensure I didn't unseat the barrel extension. Otherwise, make sure your reaction rod is solidly secured.

You can make a set of barrel blocks easily enough -

* get two short lengths of 2x4, mate them perfectly together tighten them into your vise (alternatively you could screw them together);

* use a speedbore type ( http://www.irwin.com/tools/drill-bit...speed-bit-sets ) as close to your barrel diameter as possible and dril through the 2x4's at the joint - the speedbore screw end gets you started and holds in place until the larger cutting bit engages the wood;

Attachment 52409

You say there are a couple of teeth left on the barrel nut. If the pipe wrench won't work, drive the nut off. The receiver has to be solidly mounted for this, so I would probably use the reaction rod to reduce vibration.

If you have a piece of hardwood, I would use it against the tooth, otherwise use a large machinist punch. Make sure it is solidly mounted and that the punch/board is solidly against the tooth. Use a big enough hammer to transfer some energy and sharply rap - versus pound/beat - looking for an impact that jars with as little force as possible. You can increase the power of your blows as needed, but start with a sharp rap.

You'll get it.

It's a sort of monolithic upper. You can't see but half the nut. Google it for pictures.

[26 Inf]

It's a sort of monolithic upper. You can't see but half the nut. Google it for pictures.

Oh, yeah. I looked at the Aero site, but their pics didn't give me the idea it was that recessed. This one does:

Attachment 52410

May be able to tap it, but pipe wrench definitely not an option.

[26 Inf]

A couple of things I would try before I went to welding, etc.

As I understand a couple of teeth are left. Are any threads from the barrel nut visible? If you have enough surface simply use a pipe wrench to remove the barrel nut.

Since it is 'stuck' I would try to use barrel blocks first in order to ensure I didn't unseat the barrel extension. Otherwise, make sure your reaction rod is solidly secured.

You can make a set of barrel blocks easily enough -

* get two short lengths of 2x4, mate them perfectly together tighten them into your vise (alternatively you could screw them together);

* use a speedbore type ( http://www.irwin.com/tools/drill-bit...speed-bit-sets ) as close to your barrel diameter as possible and dril through the 2x4's at the joint - the speedbore screw end gets you started and holds in place until the larger cutting bit engages the wood;

Attachment 52409

You say there are a couple of teeth left on the barrel nut. If the pipe wrench won't work, drive the nut off. The receiver has to be solidly mounted for this, so I would probably use the reaction rod to reduce vibration.

If you have a piece of hardwood, I would use it against the tooth, otherwise use a large machinist punch. Make sure it is solidly mounted and that the punch/board is solidly against the tooth. Use a big enough hammer to transfer some energy and sharply rap - versus pound/beat - looking for an impact that jars with as little force as possible. You can increase the power of your blows as needed, but start with a sharp rap.

You'll get it.

It looks like we've scared old ZKMC18 off. Just in case he's reading this, I wanted to repost my suggestions of 4 days ago.

Good luck!

ETA: the reason to use a piece of hardwood if possible, is because even though a piece of oak trim or 1x2 is harder than a piece of pine, it is still softer than the metal. If the force isn't going to be enough to loosen the nut, the wood will give before the last tooth does. In theory. When faced with situations like this Mr. Alexander (my he RIP) taught us shop kiddies to try to use a sacrificial piece of material before going to the big guns.

[titsonritz]

Pictures to follow this evening.

So when I say “wrench” I mean the wrench attachment that has grooves to fit the barrel nut.

https://aeroprecisionusa.com/m4e1-ba...ut-wrench.html

According to Aero Precision, this is a pretty common problem and it’s difficult to keep the torque wrench perfectly perpendicular.

The barrel nut is this one, with all teeth broken off.

https://aeroprecisionusa.com/cop-barrel-nut.html

That should be all you need to know about Aero. This kind of shit is SOP

Oh, yeah. I looked at the Aero site, but their pics didn't give me the idea it was that recessed. This one does:

Attachment 52410

May be able to tap it, but pipe wrench definitely not an option.

I am I missing something here? It looks to me that you should be able to remove 8 screws and remove that collar (it does look integral to me) on that POS "barrel nut" then use channel locks or even pipe to remove the barrel nut.