Help. Gas tube does not align with barrel nut!

**scottz63** · 05-13-2016, 01:49 PM

O.K. I need some advice with this one. My gas tube does not align with barrel nut when torqued to proper specs. Used proper grease on threads and torqued to nut to 30 ft. lbs. three times to get proper thread stretch. Started at 30 lbs and worked my way all the way up to the max of 80 lbs in 5 lbs increments. Barrel nut teeth still do not line up with gas tube properly. I did this procedure three times already now. It needs to go a tad more but I can't because I am already at max! What now?
I know there some choices.

1. Lap the front of the receiver a bit.
2. Use barrel shims.
3. Use a different barrel nut. (have to take off the FSB to do this one. Don't want to.)

Are there any other options? What would you do?

Thanks, Scott

**Planning** · 05-13-2016, 02:35 PM

Originally Posted by scottz63

O.K. I need some advice with this one. My gas tube does not align with barrel nut when torqued to proper specs. Used proper grease on threads and torqued to nut to 30 ft. lbs. three times to get proper thread stretch. Started at 30 lbs and worked my way all the way up to the max of 80 lbs in 5 lbs increments. Barrel nut teeth still do not line up with gas tube properly. I did this procedure three times already now. It needs to go a tad more but I can't because I am already at max! What now?
I know there some choices.

1. Lap the front of the receiver a bit.
2. Use barrel shims.
3. Use a different barrel nut. (have to take off the FSB to do this one. Don't want to.)

Are there any other options? What would you do?

Thanks, Scott

OK! first just stop for a little bit.
Put it up. read this.
go watch a tv show or something.

Come back a read this again.
This is only a suggestion.

What kind of lube are you using on the threads?

I try to never take the barrel nut off, Removing the FSB is not a good thing. It is difficult to get it to go back on with the correct line up. It has taken me a lot of time to get it to line up correctly again when I have tried it.

1. Why shims?
2. I have never added shims.
3. why lap the receiver, you are using a standard barrel nut?
4. I usually torque to 30 to 35#'s, release and re- torque to #40 pounds, This should get you close.
loosen the nut again and torque to where the hole for the gas tube line almost up on the nut.
( I use an old piece of gas tube) where it goes into where the gas tube will go into the receiver.
I tried the eye ball looking and that never worked for me.
I need something mechanical in the hole to line it up.
If you go too far then you have to try again, then it get really hard to hit the next line up.
Tighten it until the gas tube slide easy in and out and stop tightening.
I go for any thing over 40#'s and stop.
I usually hit pretty close to 45"s.
STOP! That is enough.

Sounds like you tried to get it too tight to me.
I have only had to tighten one to just over 45#'s one time.
Remember Use a breaker bar to tighten the nut. Use the torque wrench to check the tightness #'s..
Good luck.
Ron

**scottz63** · 05-13-2016, 03:31 PM

Thanks for the help. I took a break and tried again. I am using moly lithium as per lots of instructions and videos watched. At 30 lbs the tooth of the barrel nut is just starting to get in the way. At 45 lbs the tooth is dead center. At 80 lbs the tooth is almost clear but hitting the gas tube just enough to set it off center.

I have tried this half a dozen times now. Think I am going to put it up for the day before I do something stupid. Lol

Edit: It's the barrel nut that came on my new barrel from AR15sport and it's going on my A1 receiver made by NDS.

**Planning** · 05-13-2016, 04:15 PM

Originally Posted by scottz63

Thanks for the help. I took a break and tried again. I am using moly lithium as per lots of instructions and videos watched. At 30 lbs the tooth of the barrel nut is just starting to get in the way. At 45 lbs the tooth is dead center. At 80 lbs the tooth is almost clear but hitting the gas tube just enough to set it off center.

I have tried this half a dozen times now. Think I am going to put it up for the day before I do something stupid. Lol

Edit: It's the barrel nut that came on my new barrel from AR15sport and it's going on my A1 receiver made by NDS.

What are you using to clamp the receiver?

What kind (brand) of barrel wrench are you using?

I just remember a guy having a problem like this.
He was using a clam shell and had it in the vice too tight and it squeezed the threads out of round just a little.
some one told him to loosen the vice a little and he was able to get it to work. The clam shell just need to hold the receiver.

**scottz63** · 05-13-2016, 05:26 PM

Tapco wrench, nice heavy one. Wheeler vise block with anti crush insert. I don't have it too tight in the vise, just snug. It's just not lining up for me. I have half a mind to machine off the tooth on the nut, torque it to 45 lbs, and call it done.

Tapco_AR-15_Armorer_s_Tool.jpg
ViseBlockClamp.jpg

**Planning** · 05-13-2016, 06:12 PM

Originally Posted by scottz63

Tapco wrench, nice heavy one. Wheeler vise block with anti crush insert. I don't have it too tight in the vise, just snug. It's just not lining up for me. I have half a mind to machine off the tooth on the nut, torque it to 45 lbs, and call it done.

Tapco_AR-15_Armorer_s_Tool.jpg
ViseBlockClamp.jpg

Use the other half of your mind and don't machine off anything.
Something is not correct and finding it out before modifying the barrel nut is better.

The wheeler vise block and insert is what I use.
The wrench looks like what most are using.

so, maybe it is something with the barrel.

I have not had any problems with any of my NDS receivers or heard of anyone that has. ( doesn't mean someone has not)

I am guessing it is something to do with the barrel nut or barrel.
I would contact both NDS and where you got the barrel and see if they know of any problems or solutions.
Having something on a fire arm that is not correct is a scary thing to me.
If I find something not correct I fix it before using it.

**Roger Davis** · 05-13-2016, 06:32 PM

I wouldnt modify anything either. I have a couple barrel nuts i can send you to see if it would help you get your build done. PM an address, ill get hem one the way. Roger.

**scottz63** · 05-14-2016, 05:41 AM

Going to try again in a little bit after I get some coffee in me.

Got it!!! Found a tiny little imperfection on the face of the receiver. A slight touch with a jewelers file took care of it. Gas tube lined up perfect right at 45 lbs. Happy now.

Thanks for the help and suggestions Ron.

Originally Posted by Roger Davis

I wouldnt modify anything either. I have a couple barrel nuts i can send you to see if it would help you get your build done. PM an address, ill get hem one the way. Roger.

Thank you very much for the offer, but I am good now.