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Discussion Starter · #1 ·
My son bought a quad rail for his DPMS. Using a vice and wheeler armorers tool, we can't get the damn barrel nut off, even with alot of heat applied. We managed to strip all the recesses on the nut. After doing some research I was going to dremel the outside ring off, and go with a big ass pipe wrench next. Anyother suggestions.
 

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Had this with a Colt M4, used enough heat and still nothing. I tried a extension on my wench and with great effort heard a load pop followed by another and thought I was making progress, NOPE! snapped the AR vice and snapped the upper just under the ejection port. I'm still running the upper but evertime I see the crack I am reminded this upper got one over on me. :wink:

Best advise is if you feel you have used all the force and heat you feel comfortable with using, make a cut on opposite sides of the barrel nut and remove the nut that way. Just go slow and check often till you are through the nut. You might even cut as far as you feel comfortable with and use a chisel to split the two half's of the barrel nut.

Good luck, it's frustrating.
 

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Discussion Starter · #6 ·
Thanks Tal. I had it glowing with the heat gun. Was afraid to use a torch and ruin the plastic reciever clamp. I was using a 2 foot long torque wrench attached to the armorers tool, so I think I had plenty of leverage. Damn thing won't budge.
 

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Cant tell if any threadlocker was used, but we used a liberal amount of acetone after the nut started stripping.

I've had many many many DPMS AR's over the years and it was common but not regular for them to use WAY to much thread locking compound on the barrel nuts.

I've carefully used a small propane torch even in the plastic AR vices. I would guess your at the point of needing to cut the barrel nut off by now, just go slow and you'll be ok even if you nick the threads.
 

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Discussion Starter · #10 ·
I'm going to try that, kinda worried about damaging the upper, if I get any rougher with it.
I've had many many many DPMS AR's over the years and it was common but not regular for them to use WAY to much thread locking compound on the barrel nuts.

I've carefully used a small propane torch even in the plastic AR vices. I would guess your at the point of needing to cut the barrel nut off by now, just go slow and you'll be ok even if you nick the threads.
 

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Just buy a new upper. This upper because of the stresses might be toast by now if you used all that force and now have to split the nut.

Put the quads on the new upper. I am always leary about the amount of force used and the yield point of the alloy. You may save yourself problems down the road as well.
 

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Just buy a new upper. This upper because of the stresses might be toast by now if you used all that force and now have to split the nut.

Put the quads on the new upper. I am always leary about the amount of force used and the yield point of the alloy. You may save yourself problems down the road as well.
I use to be concerned till I popped my Colt upper, unless he has unusual drag on the bolt carrier group now I wouldn't worry. I have been running the cracked Colt partly as a experiment and after thousands of rounds and several years nothing has changed. With uppers being as cheap as they are it's not like he would be dropping a large sum but I wouldn't sweat it if he could get the upper apart and the barrel nut threads are not damaged to much from cutting the nut off.

My .02
 

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Upper receivers are not that expensive. Get a new one, swap the parts.
 

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You said you wanted to put a new barrel on. Now you have to replace the nut as well. An upper can be had for little more and you have a complete setup. Your way you reuse the upper and buy the nut and barrel, if the barrel will seperate from the upper anyways.

Save yourself time and effort and just buy the upper and salvage what you can if you want from the old one.
 
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