I’ve had bad luck with my first two re-barrelings. After collecting all the proper tools and reading everything I could, things just did not go as smoothly as I had anticipated. Both times the only way to get the barrel nuts indexed was with with some serious torque. Both nuts were just past alignment at 30 foot pounds. The first one finally lined up in the 70 foot pound range. The second lined up right at 80. This was only after tightening and loosening numerous times and a very liberal application of 33MS grease.
As a result of this (and my own incompetence at turning a wrench with the delta ring pushed back), both barrel nuts are a little torn up. Still functional, but they were definitely starting to strip. Some of the corners are looking a little rounded. I was wondering if it would be worthwhile to go ahead and replace them now. I’m not planning on swapping out these uppers any time soon. Just worried about them seizing up and being unable remove the barrel nuts in the distant future. I can provide pictures if you guys need them.
i dont think anybody can answer this but you… if it bugs you, then do what you need to do to make yourself comfortable. otherwise, they’re functional, right? leave 'em alone… shoot the guns… worry about possible rebarreling later.
I am a little confused, help me out. The minimum torque when installing a barrel is 30 ft./lbs and the max is 80 ft./lbs. Are you saying that you could not get eveything to line up until you were at 80?
Did you work the threads 3 times?
If everything is set now I would leave it. Out of curiousity who made the parts you were using? Particularly the barrel nut/ barrel?
In both cases I set the torque wrench to 30. Tightened three times. In both cases the barrel nut was just past index on the third tightening. On one I could actually insert the gas tube, but it was at such an angle that I would have to bend it quite a bit to get it into the FSB. I then set the wrench to 40, 60, then 80 trying to get the next hole to line up. At 80 it was just shy of lining up. I even marked the hole to make sure I was not skipping one. I then loosened and snugged a few more times and it lined up. One lined up at around 70 the other right at 80.
One was on my Noveske upper using the factory barrel nut. The other was on my buddy’s Bushmaster using the factory barrel nut. In both cases I was installing BCM (CMT?) uppers.
Any advice on how to avoid this in the future? Did I do something wrong? Did I just have bad luck?
I have encountered this issue with Bushmaster barrel nuts in the past. Not with Noveske though.
You should tighten the nut completely two times, then add some anti-seize and tighten the third time for the money. I am willing to bet that had you not used the torque wrench you would have had no issue.
those are both acceptable, if on the high limit… there’s not really anything you can do to “avoid” it other than keeping a large supply of barrel nuts on hand, and trying different ones when you’re getting out of your comfort zone. as far as keeping the tool from chewing up your spokes, that just takes practice… holding firm with one hand while applying centered, even pressure with the other.
one thing that may or may not be helpful- i haven’t ever set the torque wrench to a desired compression… i just set to 80 ft/lbs and work away. if it clicks, i know i’m about to exceed the tolerance, but so long as i get no click, i know i’m free to keep at it…\
I have a factory built 20" SPR upper that came with a few rounded and one missing barrel nut teeth.Had an RA# to do a return and decided to just leave it well enough alone it shot so well…still runs perfectly fine and approaching 3,000 rounds.
The manufacturers gunsmith said that missing or deformed barrel nut teeth may or may not affect how well the handguards fit.In my case that was not an issue so I ran with it.
So I also say leave the uppers as is if everything fits and runs.