hey all, im new here, and fairly new to the AR world. however i have been working with a buddy who has been working with them for years. we are trying the change out the handguard on my m&p15 to a one piece free float tube. how ever we are having a rediculously hard time getting the barrel nut loose, we have put it in a vice every way we can, tried heating it. did everything in our ability to break the nut free and it wont budge. anyeone got any tips? he said he has removed several of them on other brands and never had a problem. i did find out that the pins on the gas block come out opposite direction eof other brands, any chance these are reverse threads? not sure what to do, let me know what you think
barrel nut
- Thread starter nymike
- Start date
Smitty357
Well-known member
If its a mil-spec upper, i highly doubt the threads are reversed. The pins on gas block isnt important, it just depends on the direction they were beat into place. I've seen them come out in either direction.
But the barrel nut should be exact same as any mil-spec upper. The thread size should also be the same as any other mil-spec. I'd say maybe drop some croil oil down it and let it sit a few hours, maybe even sit over night........You dont want to screw the upper up trying to fight with that nut.
PS: Once u get it off, put a tiny bit of never seaze on the threads and next time u'll not have a problem getting it off.
But the barrel nut should be exact same as any mil-spec upper. The thread size should also be the same as any other mil-spec. I'd say maybe drop some croil oil down it and let it sit a few hours, maybe even sit over night........You dont want to screw the upper up trying to fight with that nut.
PS: Once u get it off, put a tiny bit of never seaze on the threads and next time u'll not have a problem getting it off.
Maddmax
US Veteran
I'd be worried about the heating. How hot did you get it ? Glowing red hot ?
Yeah you need to have the blocks, or at least a 2x4 block on the top and bottom of the receiver and put it sideways in the vise. Plus I would consider leaving the BCG and charging handle in the upper for some more support. They are pretty light and it would be possible to tweak it if not supported correctly. I havent heard of anyone having to apply heat, it would be possible to make the aluminum brittle, although it is possible to put the entire upper into the deep freezer for about 45 minutes, take it out and apply a little heat from a heat gun on the barrel nut. I have used that trick before.
That is why I would leave the BCG and Charging handle in. It helps provide internal bracing. Just a thought!
oberon
Well-known member
You can find the whole setup....I can't remember....... (Sportsmans? Cheaper'n dirt) .....anyway the lower magwell block, the 'clamshell' upper receiver fixture, complete with dummy BCG plug. I spent less than $50.
I did 3 of ours and the new factory uppers were the worst challenge to get apart. I pretty much wrecked my low-end armorer's wrench. I got a solid steel/ welded pins GI one from DPMS for, like $10. Much better. It is worth having the right setup if you are going to do ARs
Cheaper than torquin' the 'nads off an upper.
Nevrseez is pretty much esssential. And when you go to snug that bad boy up, don't over do it.
There is a bench method that will put the actual torque value on the threads right smack in the spec range, without tryin' to duplicate the published numbers in the technical material or gettin' all worked up about it.
Slap a little nevrseez on the threads and start the nut on and crank up hand tight. Then loosen and repeat 2 more times. Tighen it up snug and move it over just to the next notch or hole( depending on what nut you're using, and line it up on the gas key with an appropriately sized drill bit shank. It does not take much, and it is easy to overdo it if you are heavy handed. Run the nut on & off, in & out a couple times . You will fine the sweet spot.
Then go out and blast away with that thing.
I did 3 of ours and the new factory uppers were the worst challenge to get apart. I pretty much wrecked my low-end armorer's wrench. I got a solid steel/ welded pins GI one from DPMS for, like $10. Much better. It is worth having the right setup if you are going to do ARs
Cheaper than torquin' the 'nads off an upper.
Nevrseez is pretty much esssential. And when you go to snug that bad boy up, don't over do it.
There is a bench method that will put the actual torque value on the threads right smack in the spec range, without tryin' to duplicate the published numbers in the technical material or gettin' all worked up about it.
Slap a little nevrseez on the threads and start the nut on and crank up hand tight. Then loosen and repeat 2 more times. Tighen it up snug and move it over just to the next notch or hole( depending on what nut you're using, and line it up on the gas key with an appropriately sized drill bit shank. It does not take much, and it is easy to overdo it if you are heavy handed. Run the nut on & off, in & out a couple times . You will fine the sweet spot.
Then go out and blast away with that thing.
JaPes
Well-known member
Stebo
Well-known member
This is what scared me away from a free float installation that required thread lock!
One thing to keep in mind when using heat on the barrel nut - the receiver is aluminum, the nut is steel. Aluminum has a higher expansion coefficient than steel, so heat applied in the wrong manner could make the situation worse. Grover suggests cold soaking in a freezer, great idea, but you might then try a conservative application of heat to the nut and immediately applying torque.
For certain, the nut goes on in one direction, and comes off the opposite (CCW). There's not much mystery there. You must have the receiver solidly clamped in a bench vise with no give to it. If still no success, your options are a longer breaker bar or, as someone suggested, getting creative with a Dremel. Good luck.
so, anyone kneow if any one of the m&p models that were ny compliants, were the barrels pinned, i brought it to an unofficial gunsmith, that builds alot of bolt guns and some ars, he felt like, and confirmed with another ar specialist that there was nooo way it should have been that tight, so he milled it off, and in the process he hit something in the nut that sure looked like a pin to us, and thats the only thing we could figure why it was impossible to break free
Kodiakco
Well-known member
I've never heard of any barrel nut being pinned. the only pin in that area that I'm aware of is the barrel indexing pin
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