Site Notices
10/30/2014 3:55:04 PM
ARCHIVED ARCHIVED
  Previous Page
Page:  / 2
Author
Message
Garandboy
Member
Offline
Posts: 3139
Feedback: 100% (16)
Posted: 2/13/2011 7:50:10 PM
You know how some barrel and upper combos can be a pain to get the gas tube holes to line up? Well I ran into a real hard case today.

Either super tight or hand tight, no in between. I'm going to swap the barrel to another upper to see if it helps. But does any one make shims that can be used to help align problem barrels?
Handy little carbine. The M44 is a combination flash bang grenade, flame thrower, rifle and spear all in one.
iNeXile556
Deo vindice
Military
Offline
Posts: 1322
Feedback: 100% (22)
Link To This Post
Posted: 2/13/2011 7:58:01 PM
[Last Edit: 2/13/2011 7:58:41 PM by iNeXile556]
I use a big flat diamond sharping stone to take a bit off the barrel nut. That loosens up the "Super tight" position.
I guess you could use some fine emery cloth on a nice flat surface to do the same thing. Keep checking for fit.

I'm guessing you tried the repeated tighten and loosen method already.
"Nothing is more terrifying than ignorance in action" - Goethe, proven true November 4th, 2008

"For a people who are free, and who mean to remain so, a well organized and armed militia is their best security". - Thomas Jefferson
Garandboy
Member
Offline
Posts: 3140
Feedback: 100% (16)
Link To This Post
Posted: 2/13/2011 8:08:37 PM
Yep, tried the tighten and loosen several times. Close but no cigar. How do you remove an even amount from the face of the barrel nut? I've installed a few dozen barrels and have never seen one this tough. Real bad.
Handy little carbine. The M44 is a combination flash bang grenade, flame thrower, rifle and spear all in one.
458winmag
Member
Offline
Posts: 2935
Feedback: 100% (83)
Link To This Post
Posted: 2/13/2011 9:06:32 PM
I'd start thinking about lapping the upper
CAC01
Member
Offline
Posts: 528
Feedback: 100% (82)
Link To This Post
Posted: 2/13/2011 9:17:46 PM
Originally Posted By Garandboy:
Yep, tried the tighten and loosen several times. Close but no cigar. How do you remove an even amount from the face of the barrel nut? I've installed a few dozen barrels and have never seen one this tough. Real bad.


You can't! This is bad advice, really bad advice.

This topic keeps coming up but people just won't listen. Where did a torque wrench come into play during surgery? Torque that nut to 30 ft lbs then tighten it to the next notch in the barrel nut. It's that simple.
Garandboy
Member
Offline
Posts: 3141
Feedback: 100% (16)
Link To This Post
Posted: 2/13/2011 9:27:32 PM
Originally Posted By CAC01:
Originally Posted By Garandboy:
Yep, tried the tighten and loosen several times. Close but no cigar. How do you remove an even amount from the face of the barrel nut? I've installed a few dozen barrels and have never seen one this tough. Real bad.


You can't! This is bad advice, really bad advice.

This topic keeps coming up but people just won't listen. Where did a torque wrench come into play during surgery? Torque that nut to 30 ft lbs then tighten it to the next notch in the barrel nut. It's that simple.


That's part of the problem. It's the strangest thing i have seen. Line up one notch, then over 80 pounds to the next and it will not line up. Back it up to the previous notch and it's hand tight at best. It goes from super tight to loose. I can turn the barrel by hand in the receiver when lined up.

I can lap it I guess.

Handy little carbine. The M44 is a combination flash bang grenade, flame thrower, rifle and spear all in one.
CAC01
Member
Offline
Posts: 529
Feedback: 100% (82)
Link To This Post
Posted: 2/13/2011 9:52:27 PM
The top value is irrelevant. Just tighten it to the next notch.
JoshAston
Sardonic Cynic
Military
Offline
Posts: 10766
Feedback: 100% (31)
Link To This Post
Posted: 2/13/2011 10:14:03 PM

Originally Posted By CAC01:
The top value is irrelevant. Just tighten it to the next notch.

No it's not. You go too far past that 80 ft-lbs and you'll crack your upper.
All skill is in vain when an angel pisses down the touch hole of your musket
mybronco2
Offline
Posts: 355
Feedback: 0% (0)
Link To This Post
Posted: 2/13/2011 11:31:26 PM
lap upper or try another nut. Its not like the threads on the nut are indexed to the area you grab with the wrench.
Mine was a PITA too, and I told myself next time, Im building a upper, I will get 2 or 3 barrel nuts so I can pick a better fit.
458winmag
Member
Offline
Posts: 2938
Feedback: 100% (83)
Link To This Post
Posted: 2/13/2011 11:46:42 PM
Originally Posted By mybronco2:
lap upper or try another nut. Its not like the threads on the nut are indexed to the area you grab with the wrench.
Mine was a PITA too, and I told myself next time, Im building a upper, I will get 2 or 3 barrel nuts so I can pick a better fit.


Damn, I keep forgetting this option.
Well done
Garandboy
Member
Offline
Posts: 3142
Feedback: 100% (16)
Link To This Post
Posted: 2/14/2011 12:55:11 AM
Originally Posted By 458winmag:
Originally Posted By mybronco2:
lap upper or try another nut. Its not like the threads on the nut are indexed to the area you grab with the wrench.
Mine was a PITA too, and I told myself next time, Im building a upper, I will get 2 or 3 barrel nuts so I can pick a better fit.


Damn, I keep forgetting this option.
Well done


This is a YHM float tube with it's own nut. Only one I have for that type of tube. But good idea if it was a standard build. Of course I've never had this extreme issue with a factory style nut.

Handy little carbine. The M44 is a combination flash bang grenade, flame thrower, rifle and spear all in one.
JoshAston
Sardonic Cynic
Military
Offline
Posts: 10769
Feedback: 100% (31)
Link To This Post
Posted: 2/14/2011 1:02:45 AM

Originally Posted By Garandboy:
Originally Posted By 458winmag:
Originally Posted By mybronco2:
lap upper or try another nut. Its not like the threads on the nut are indexed to the area you grab with the wrench.
Mine was a PITA too, and I told myself next time, Im building a upper, I will get 2 or 3 barrel nuts so I can pick a better fit.


Damn, I keep forgetting this option.
Well done


This is a YHM float tube with it's own nut. Only one I have for that type of tube. But good idea if it was a standard build. Of course I've never had this extreme issue with a factory style nut.

Call YHM and ask for another nut.

All skill is in vain when an angel pisses down the touch hole of your musket
458winmag
Member
Offline
Posts: 2941
Feedback: 100% (83)
Link To This Post
Posted: 2/14/2011 1:09:10 AM
Why do folks not post all the facts from the get go
Primos
Offline
Posts: 13301
Feedback: 100% (44)
Link To This Post
Posted: 2/14/2011 1:55:33 AM
There's probably nothing wrong with the barrel nut.
ziarifleman
Ideologically Incompatible
Online
Posts: 17641
Feedback: 100% (6)
Link To This Post
Posted: 2/14/2011 1:58:43 AM

Originally Posted By Garandboy:
Yep, tried the tighten and loosen several times. Close but no cigar. How do you remove an even amount from the face of the barrel nut? I've installed a few dozen barrels and have never seen one this tough. Real bad.

With a lathe and a boring bar.
"I have seen everything during my lifetime of futility; there is a righteous man who perishes in his righteousness and there is a wicked man who prolongs his life in his wickedness."

ziarifleman
Ideologically Incompatible
Online
Posts: 17642
Feedback: 100% (6)
Link To This Post
Posted: 2/14/2011 1:59:50 AM
Are you using moly grease on it?
"I have seen everything during my lifetime of futility; there is a righteous man who perishes in his righteousness and there is a wicked man who prolongs his life in his wickedness."

GHPorter
That One Member
Military
Offline
Posts: 9863
Feedback: 100% (4)
Link To This Post
Posted: 2/14/2011 6:43:09 AM
Originally Posted By ziarifleman:
Are you using moly grease on it?


This is my very first question in this sort of situation. Any decent anti-seize grease is absolutely essential, and "the right" grease pretty darn important. The "30-80 ft/lb" torque spec is based on a standard barrel nut being assembled with the appropriate MIL-G grease. The TM calls for tighten/torque/loosen/retorque if you can't get the desired number, and some people have reported repeating the process more than 10 times.

But the next issue is what YHM says about the torque spec for THAT unit. If they say "use the standard torque spec," then that's fine. They may ask for something different, based on the materials and treatment of the parts. Also, how are you connecting the torque wrench to the YHM barrel nut? That could make a difference.
"--you can't conquer a free man; the most you can do is kill him."
Heinlein
j3_
Member
Offline
Posts: 5388
Feedback: 100% (60)
Link To This Post
Posted: 2/14/2011 7:27:02 AM
Easiest way is what has already been said. Lap the front of the upper. I use 600 grit paper on the flat side of a large socket. Most time you will not even go through the anodizing before it will allow the notch to line up. You only have to remove a .001 to .0015.
I had a barrel extension unscrew yesterday on a DSA barrel using barrel blocks with the wrench set at 70 FT LBS. Going over the manual stated 80 LBs is not a good idea.

160$ barrel in the trash
BeerBender
Member
Offline
Posts: 466
Feedback: 0% (0)
Link To This Post
Posted: 2/14/2011 9:57:55 AM
Originally Posted By 458winmag:
Why do folks not post all the facts from the get go


So the thread can go 3 times longer than it needs to be.

Garandboy
Member
Offline
Posts: 3145
Feedback: 100% (16)
Link To This Post
Posted: 2/14/2011 11:34:50 AM
[Last Edit: 2/14/2011 11:36:26 AM by Garandboy]
Originally Posted By BeerBender:
Originally Posted By 458winmag:
Why do folks not post all the facts from the get go


So the thread can go 3 times longer than it needs to be.



Does the type of nut really matter? I just installed an SAR, and this tube on another upper. The problem would be the same regardless of who made the nut or what rail, no? I just never ran into one this tough before.

Tell me exactly how the fact that the fucking nut is a YHM has extended this three times longer? The lapping and other advice remains the same.
Handy little carbine. The M44 is a combination flash bang grenade, flame thrower, rifle and spear all in one.
WVUChrome
Offline
Posts: 67
Feedback: 100% (1)
Link To This Post
Posted: 2/14/2011 11:53:59 AM
Why not simply torque over minimum, then remove the offending nub?

Later,
Chrome...
Garandboy
Member
Offline
Posts: 3146
Feedback: 100% (16)
Link To This Post
Posted: 2/14/2011 1:51:50 PM
Lapped the receiver, problem solved. Thanks guys.
Handy little carbine. The M44 is a combination flash bang grenade, flame thrower, rifle and spear all in one.
gee223
Offline
Posts: 2834
Feedback: 100% (2)
Link To This Post
Posted: 2/14/2011 4:19:20 PM
Originally Posted By j3_:
Easiest way is what has already been said. Lap the front of the upper. I use 600 grit paper on the flat side of a large socket. Most time you will not even go through the anodizing before it will allow the notch to line up. You only have to remove a .001 to .0015.
I had a barrel extension unscrew yesterday on a DSA barrel using barrel blocks with the wrench set at 70 FT LBS. Going over the manual stated 80 LBs is not a good idea.

160$ barrel in the trash

DSA may replace the barrel for you, or have another alignment pin pressed in it for you. Cal them before scrapping it.
PursuitSS
...believe in me, I'm with the High Command.
Offline
Posts: 2871
Feedback: 100% (24)
Link To This Post
Posted: 2/14/2011 4:53:06 PM
Randall at AR15barrels.com offers shims to index the barrel nut. That being said, Randall is MIA from this web site because of several questionable business transactions!!!

Link to barrel indexing shims FAQ

If you need further info on Randall, contact Aimless (site staff)
"When trading bullets it is better to give than to receive"

"Take your money and a traveler's bag. And if you don't have a sword, sell your clothes and buy one!" Jesus Christ - Luke 22.36

NRA Endowment Member
iNeXile556
Deo vindice
Military
Offline
Posts: 1327
Feedback: 100% (22)
Link To This Post
Posted: 2/14/2011 5:20:54 PM
[Last Edit: 2/14/2011 5:30:58 PM by iNeXile556]


"Nothing is more terrifying than ignorance in action" - Goethe, proven true November 4th, 2008

"For a people who are free, and who mean to remain so, a well organized and armed militia is their best security". - Thomas Jefferson
Garandboy
Member
Offline
Posts: 3148
Feedback: 100% (16)
Link To This Post
Posted: 2/14/2011 5:51:31 PM
Originally Posted By PursuitSS:
Randall at AR15barrels.com offers shims to index the barrel nut. That being said, Randall is MIA from this web site because of several questionable business transactions!!!

Link to barrel indexing shims FAQ

If you need further info on Randall, contact Aimless (site staff)


I didn't think Randall was still in business. Just noticed in my Spikes directions that they mention shims for the SAR if you are using a piston with that rail.

Handy little carbine. The M44 is a combination flash bang grenade, flame thrower, rifle and spear all in one.
  Previous Page
Page:  / 2
ARCHIVED ARCHIVED