AR barrel extension coming loose! - Page 1

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[ARCHIVED THREAD] - AR barrel extension coming loose!

Posted: 1/22/2016 9:41:22 PM EDT

Today I was removing the barrel from my 300BLK SBR upper and when I was trying to remove the muzzle break the barrel twisted and bent my gas tube. The barrel was still attached to the upper. I was able to free the barrel nut after removing the bent gas tube. once everything was apart, i noticed the barrel was unscrewing from the barrel extension. I still was not able to move the muzzle break yet, I kind of gave up and ran out of time before work. Anyways, how are barrel extensions mounted on the barrel and do i need to get it head spaced? Is this something I can do, or is it something for a gun smith?

and no i cannot contact the company i bought it from, they closed shop in 2013. I bought it from Ole's Gun Shop in Oregon. It is a Shilen barrel with a Stag Arms extension. i have shot less than 200rds out of the barrel.

how screwed am i?

Posted: 1/22/2016 10:03:28 PM EDT

[#1]

Quoted:
how screwed am i?

View Quote

Very.

First, I presume you were using a reaction rod type device, and your experience is why they are not a good tool for most tasks. Or if you were using receiver blocks, those are an even worse choice for muzzle device work. For high torque muzzle device work you need barrel blocks. Are you 100% sure you aren't dealing with a permanently attached muzzle brake?

How much torque were you genuinely using? Spec torque on barrel extensions is 150 ft/lbs although as we have seen tons of AR barrels are far under that torque.

If you had an inexpensive barrel everyone (including me) would probably just inform you that you now own a paperweight. In this particular case it may be worth trying to salvage. Basically you'll need to torque the barrel extension back on, aligning it to top dead center and hopefully it'll be at some reasonable torque value when it gets there. Then check headspace. There is more that could be done if need be but its not trivial at all.

Is this a custom barrel that was made with the Stag extension (maybe for a left hand upper?), or did someone swap extensions?

Posted: 1/22/2016 10:05:52 PM EDT

[#2]

That barrel is toast. Time for a new one.

Posted: 1/22/2016 10:18:11 PM EDT

[#3]

I was reading a post on another board on s smith that was redoing extensions without any problems. If I run across it I'll post it up. There is hope yet.

Greg

Posted: 1/22/2016 10:21:03 PM EDT

[#4]

Contact ADCO.

They can make it workout for you if you don't want to replace the barrel.

Wes

Posted: 1/22/2016 10:21:43 PM EDT

[#5]

Quote History

Quoted:

Very.

First, I presume you were using a reaction rod type device, and your experience is why they are not a good tool for most tasks. Or if you were using receiver blocks, those are an even worse choice for muzzle device work. For high torque muzzle device work you need barrel blocks. Are you 100% sure you aren't dealing with a permanently attached muzzle brake?

How much torque were you genuinely using? Spec torque on barrel extensions is 150 ft/lbs although as we have seen tons of AR barrels are far under that torque.

If you had an inexpensive barrel everyone (including me) would probably just inform you that you now own a paperweight. In this particular case it may be worth trying to salvage. Basically you'll need to torque the barrel extension back on, aligning it to top dead center and hopefully it'll be at some reasonable torque value when it gets there. Then check headspace. There is more that could be done if need be but its not trivial at all.

Is this a custom barrel that was made with the Stag extension (maybe for a left hand upper?), or did someone swap extensions?

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Quoted:

Quoted:
how screwed am i?

Very.

First, I presume you were using a reaction rod type device, and your experience is why they are not a good tool for most tasks. Or if you were using receiver blocks, those are an even worse choice for muzzle device work. For high torque muzzle device work you need barrel blocks. Are you 100% sure you aren't dealing with a permanently attached muzzle brake?

How much torque were you genuinely using? Spec torque on barrel extensions is 150 ft/lbs although as we have seen tons of AR barrels are far under that torque.

If you had an inexpensive barrel everyone (including me) would probably just inform you that you now own a paperweight. In this particular case it may be worth trying to salvage. Basically you'll need to torque the barrel extension back on, aligning it to top dead center and hopefully it'll be at some reasonable torque value when it gets there. Then check headspace. There is more that could be done if need be but its not trivial at all.

Is this a custom barrel that was made with the Stag extension (maybe for a left hand upper?), or did someone swap extensions?

i installed the muzzle break, it is a 51t. i did soak it for over 24 hours and i hardly use more than two drops of rocksett. frankly, i wasn't using that much torque at all on the muzzle break, at first i was like, wow, that was barely on there then i realized everything moved. the extension was installed and torqued by Ole's, i don't want to mess with the extensions. anyways, i installed the barrel once and hardly shot it, so i was taking it apart to install a different barrel.

ETA: i was going to just hold on to the barrel until i needed money for another project, but this kind of messed up those plans.

Posted: 1/22/2016 10:28:14 PM EDT

[#6]

Quote History

Quoted:
Contact ADCO.

They can make it workout for you if you don't want to replace the barrel.

Wes

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if i can't find anyone locally or an easy fix, they were on top of my list if i need work done.

Posted: 1/22/2016 10:33:12 PM EDT

[#7]

On my nitride debacle , White Oak Armament, was able to put a new one on for $65. It was there barrel, but they may be as to help you out.

http://www.ar15.com/forums/t_3_118/641642_A_warning_for_those_who_want_to_nitride_their_AR15_barrel___Barrel_came_loose_from_the_extension_.html&page=1

Posted: 1/22/2016 11:38:49 PM EDT

[#8]

Quote History

Quoted:

i installed the muzzle break, it is a 51t. i did soak it for over 24 hours and i hardly use more than two drops of rocksett. frankly, i wasn't using that much torque at all on the muzzle break, at first i was like, wow, that was barely on there then i realized everything moved. the extension was installed and torqued by Ole's, i don't want to mess with the extensions. anyways, i installed the barrel once and hardly shot it, so i was taking it apart to install a different barrel.

ETA: i was going to just hold on to the barrel until i needed money for another project, but this kind of messed up those plans.

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Quoted:

Quoted:
how screwed am i?

Very.

First, I presume you were using a reaction rod type device, and your experience is why they are not a good tool for most tasks. Or if you were using receiver blocks, those are an even worse choice for muzzle device work. For high torque muzzle device work you need barrel blocks. Are you 100% sure you aren't dealing with a permanently attached muzzle brake?

How much torque were you genuinely using? Spec torque on barrel extensions is 150 ft/lbs although as we have seen tons of AR barrels are far under that torque.

If you had an inexpensive barrel everyone (including me) would probably just inform you that you now own a paperweight. In this particular case it may be worth trying to salvage. Basically you'll need to torque the barrel extension back on, aligning it to top dead center and hopefully it'll be at some reasonable torque value when it gets there. Then check headspace. There is more that could be done if need be but its not trivial at all.

Is this a custom barrel that was made with the Stag extension (maybe for a left hand upper?), or did someone swap extensions?

i installed the muzzle break, it is a 51t. i did soak it for over 24 hours and i hardly use more than two drops of rocksett. frankly, i wasn't using that much torque at all on the muzzle break, at first i was like, wow, that was barely on there then i realized everything moved. the extension was installed and torqued by Ole's, i don't want to mess with the extensions. anyways, i installed the barrel once and hardly shot it, so i was taking it apart to install a different barrel.

ETA: i was going to just hold on to the barrel until i needed money for another project, but this kind of messed up those plans.

What tools were you using?

Posted: 1/22/2016 11:50:32 PM EDT

[#9]

Quote History

Quoted:

What tools were you using?

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Quoted:

Quoted:
how screwed am i?

Very.

First, I presume you were using a reaction rod type device, and your experience is why they are not a good tool for most tasks. Or if you were using receiver blocks, those are an even worse choice for muzzle device work. For high torque muzzle device work you need barrel blocks. Are you 100% sure you aren't dealing with a permanently attached muzzle brake?

How much torque were you genuinely using? Spec torque on barrel extensions is 150 ft/lbs although as we have seen tons of AR barrels are far under that torque.

If you had an inexpensive barrel everyone (including me) would probably just inform you that you now own a paperweight. In this particular case it may be worth trying to salvage. Basically you'll need to torque the barrel extension back on, aligning it to top dead center and hopefully it'll be at some reasonable torque value when it gets there. Then check headspace. There is more that could be done if need be but its not trivial at all.

Is this a custom barrel that was made with the Stag extension (maybe for a left hand upper?), or did someone swap extensions?

i installed the muzzle break, it is a 51t. i did soak it for over 24 hours and i hardly use more than two drops of rocksett. frankly, i wasn't using that much torque at all on the muzzle break, at first i was like, wow, that was barely on there then i realized everything moved. the extension was installed and torqued by Ole's, i don't want to mess with the extensions. anyways, i installed the barrel once and hardly shot it, so i was taking it apart to install a different barrel.

ETA: i was going to just hold on to the barrel until i needed money for another project, but this kind of messed up those plans.

What tools were you using?

just a small (maybe 10" long) adjustable end wrench on the muzzle break. upper was installed in a Wheeler upper vise block. i'll definitely look into a barrel block from here on out.

Posted: 1/23/2016 7:36:50 AM EDT

[#10]

The good news is that you now have a barrel for your dedicated .22 AR.

Posted: 1/23/2016 10:49:23 AM EDT

[#11]

Sounds like another vote for building/owning a complete upper for each barrel...

Best of Luck, hope you get it sorted out with minimal cost

Posted: 1/23/2016 2:18:11 PM EDT

[#12]

Quote History

Quoted:
The good news is that you now have a barrel for your dedicated .22 AR.

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How is a 300 AAC barrel good for 22?

Posted Via AR15.Com Mobile

Posted: 1/23/2016 3:18:26 PM EDT

[#13]

The only good news, is that the extension coming loose might have saved your upper from being trashed.

Posted: 1/23/2016 3:18:44 PM EDT

[#14]

Wrap the barrel with a leather belt and clamp it directly into the vice. this wont help with the barrel extension. But it will allow you to remove the muzzle break. Without further damage

Posted: 1/23/2016 5:47:50 PM EDT

[#15]

thank you all for the comments. i appreciate all the help and expertise on this forum.

Posted: 1/24/2016 12:50:38 AM EDT

[#16]

Is the barrel nitride coated? I have seen quite a few of these in the last year with the same problem. Companies finish the barrel and send them out for nitride....in the process of heating them....they come loose. Black nitride involves heating the barrel to 1000 degrees Fahrenheit......not good for a barrel extension that has been hardened during manufacture prior to installation.
The barrel extension is supposed to be torqued to 160 ft pounds on a 5.56 barrel.......so nothing you did caused the problem......the barrel was defective to begin with. If it is nitride hardened ....only recourse is to literally sit down with a box of extensions and screw them on until you find one that is hand tight with the index pin about 10 degrees counterclockwise of the gas port....then torque until it lines up.........No guarantees but if you'd like to send it in , I have about 100 extensions that aren't modded for 45's yet...be happy to give it a try for you....
(the above applies if your barrel has a standard front sight base)

If you are free floating and going with a low profile....torque a new extension on.....plug the port and drill a new one.....won't hurt a thing.

Just re-read you original post........with a split clamp low profile gas block....this is an easy fix......new extension placing the original port at least 90 degrees from the index pin......drill a new port, check headspace and enjoy..

Posted: 1/24/2016 1:47:54 AM EDT

[#17]

Quote History

Quoted:
Is the barrel nitride coated? I have seen quite a few of these in the last year with the same problem. Companies finish the barrel and send them out for nitride....in the process of heating them....they come loose. Black nitride involves heating the barrel to 1000 degrees Fahrenheit......not good for a barrel extension that has been hardened during manufacture prior to installation.
The barrel extension is supposed to be torqued to 160 ft pounds on a 5.56 barrel.......so nothing you did caused the problem......the barrel was defective to begin with. If it is nitride hardened ....only recourse is to literally sit down with a box of extensions and screw them on until you find one that is hand tight with the index pin about 10 degrees counterclockwise of the gas port....then torque until it lines up.........No guarantees but if you'd like to send it in , I have about 100 extensions that aren't modded for 45's yet...be happy to give it a try for you....
(the above applies if your barrel has a standard front sight base)

If you are free floating and going with a low profile....torque a new extension on.....plug the port and drill a new one.....won't hurt a thing.

Just re-read you original post........with a split clamp low profile gas block....this is an easy fix......new extension placing the original port at least 90 degrees from the index pin......drill a new port, check headspace and enjoy..

View Quote

the barrel is not nitrided. I owned this barrel since early 2012. i think my next step is sending the barrel to someone who is qualified to attach the extension to the barrel. this is something i don't want to mess with.

Posted: 1/24/2016 3:51:50 PM EDT

[#18]

Like others have said. Hold the barrel with a barrel block. I made mine out of a couple blocks of wood. Just bore a hole in a block of wood. Then cut it length wise down the hole. Wrap the barrel with an old inner tube if you need more traction.

Posted: 2/6/2016 8:03:17 PM EDT

[#19]

Update: i was finally able to get the muzzle break off. i had to use the inner tube trick. it was pretty easy actually. i sent ADCO an email and they replied that they do not offer that service and that if the extension is really loose, the barrel is junk. i cannot turn the extension with my hands at all. if it moves, its about an inch or so while it is in a vice. i want to know, can this be fixed by a professional or is the barrel really junked? i don't understand how a possible broken index pin junks a barrel. can't it be saved with a re-torque of the extension and re-pin?

Posted: 2/6/2016 8:13:47 PM EDT

[#20]

The index pin DOES NOT hold the barrel extension on.

First you say that the barrel extension is loose and now you say it's not?

Quoted:
i think my next step is sending the barrel to someone who is qualified to attach the extension to the barrel.

View Quote

The people who attach barrel extensions are barrel manufacturers.

The critical aspect of headspace is set by the relationship of the chamber cut into the barrel itself, to the locking lugs located on the extension. The gas port and gas block mounting (if any) cut in the barrel also have to align with the orientation of the locking lugs in the extension. This junction also has to have an adequate torque to withstand the stresses it's under, thermal cycling and such and not come loose.

The traditional way is to short chamber the barrel, torque on the extension, then finish ream the chamber to the extension to set the headspace. Then gas port is drilled using the extension to define TDC.

There are apparently many large-scale manufacturers who precut chambers to particular thread locations, with matching specifically threaded extensions so that the barrel itself is all done then the extension is attached. During that process the torque values will likely be somewhat variable as it all depends on exactly how well they can hold their machining specifications. I strongly suspect this process being out of whack is the genesis of all the loose barrel extension experiences over the last several years.

Posted: 2/6/2016 8:18:32 PM EDT

[#21]

Quote History

Quoted:
The index pin DOES NOT hold the barrel extension on.

First you say that the barrel extension is loose and now you say it's not?

View Quote

it only moves if i try to tight or loosen the muzzle device. i cannot turn the extension by hand. sorry if i'm confusing people.

Posted: 2/6/2016 8:29:15 PM EDT

[#22]

Quote History

Quoted:

it only moves if i try to tight or loosen the muzzle device. i cannot turn the extension by hand. sorry if i'm confusing people.

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Quoted:

Quoted:
The index pin DOES NOT hold the barrel extension on.

First you say that the barrel extension is loose and now you say it's not?

it only moves if i try to tight or loosen the muzzle device. i cannot turn the extension by hand. sorry if i'm confusing people.

You're still trying to torque on a muzzle device using a barrel extension tool?

This doesn't make any sense, it's a threaded fastener. Either it's tight and doesn't move, or it's loose and does. If it moves with a significant amount of drag then maybe part of the index pin got sheared off and is stuck in the threads? Or your barrelsmith is clueless and used threadlocker on a barrel extension or something like that.

I would say to send it back to whoever made the barrel, but they apparently didn't do an adequate job the first time around.

Posted: 2/6/2016 8:39:57 PM EDT

[#23]

Quote History

Quoted:

This doesn't make any sense, it's a threaded fastener. Either it's tight and doesn't move, or it's loose and does. If it moves with a significant amount of drag then maybe part of the index pin got sheared off and is stuck in the threads? Or your barrelsmith is clueless and used threadlocker on a barrel extension or something like that.

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Quoted:

Quoted:
The index pin DOES NOT hold the barrel extension on.

First you say that the barrel extension is loose and now you say it's not?

it only moves if i try to tight or loosen the muzzle device. i cannot turn the extension by hand. sorry if i'm confusing people.

This doesn't make any sense, it's a threaded fastener. Either it's tight and doesn't move, or it's loose and does. If it moves with a significant amount of drag then maybe part of the index pin got sheared off and is stuck in the threads? Or your barrelsmith is clueless and used threadlocker on a barrel extension or something like that.

ok, lets see if i can clear it up... when in a vise, the barrel will move about an inch back and forth, but only if i use a tool on a muzzle device. i cannot move the barrel with my hands.

here's an awesome late-breaking update: the gunsmith just got back to me. he said to mail it to him and he will fix it up. here's to hoping and praying that it can be fixed easily!

Posted: 2/6/2016 8:52:52 PM EDT

[#24]

Quote History

Quoted:

ok, lets see if i can clear it up... when in a vise, the barrel will move about an inch back and forth, but only if i use a tool on a muzzle device. i cannot move the barrel with my hands.

here's an awesome late-breaking update: the gunsmith just got back to me. he said to mail it to him and he will fix it up. here's to hoping and praying that it can be fixed easily!

View Quote View All Quotes

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Quote History

Quoted:

Quoted:
The index pin DOES NOT hold the barrel extension on.

First you say that the barrel extension is loose and now you say it's not?

it only moves if i try to tight or loosen the muzzle device. i cannot turn the extension by hand. sorry if i'm confusing people.

This doesn't make any sense, it's a threaded fastener. Either it's tight and doesn't move, or it's loose and does. If it moves with a significant amount of drag then maybe part of the index pin got sheared off and is stuck in the threads? Or your barrelsmith is clueless and used threadlocker on a barrel extension or something like that.

ok, lets see if i can clear it up... when in a vise, the barrel will move about an inch back and forth, but only if i use a tool on a muzzle device. i cannot move the barrel with my hands.

here's an awesome late-breaking update: the gunsmith just got back to me. he said to mail it to him and he will fix it up. here's to hoping and praying that it can be fixed easily!

If the barrel is in a vise, and you torque on the muzzle device, how does that have anything to do with the barrel extension?

Or are you still torquing on the muzzle device with the upper in a receiver block?!?!

I would have serious reservations about any gunsmith fixing it up in a sufficient way if it's actually a loose barrel extension.

Please post some photos so I can try to figure out what is happening. If you're still doing all this with a receiver block you probably just sheared off the index pin and/or trashed the upper receiver (maybe both).

Posted: 2/6/2016 9:14:05 PM EDT

[#25]

Quote History

Quoted:

If the barrel is in a vise, and you torque on the muzzle device, how does that have anything to do with the barrel extension?
ok, now i think i understand our confusion. i know the extension moves because when the barrel was still attached to the upper with the barrel nut installed, that's when the extension started letting the barrel to move. the extension gave a "pop" when it let go, i thought it was the muzzle break, but it was not.

Or are you still torquing on the muzzle device with the upper in a receiver block?!?!
no, i took the barrel off the upper, but after the incident. that probably was my biggest mistake. i tried to take off the muzzle device without using a barrel vise. i was able to get the break off putting the barrel in a vise wrapped with a bike inner tube with wood on both sides of the vise. it came off pretty easily after that.

I would have serious reservations about any gunsmith fixing it up in a sufficient way if it's actually a loose barrel extension.
i am relieved he is willing to look at it. i guess i'll have to wait to see what he says.

Please post some photos so I can try to figure out what is happening. If you're still doing all this with a receiver block you probably just sheared off the index pin and/or trashed the upper receiver (maybe both).
the upper looks to be fine. i will try to get some pics tomorrow if i have time. i will try to show how much movement there is by marking the barrel with before/after pics.

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Quote History

Quoted:

Quoted:
The index pin DOES NOT hold the barrel extension on.

First you say that the barrel extension is loose and now you say it's not?

it only moves if i try to tight or loosen the muzzle device. i cannot turn the extension by hand. sorry if i'm confusing people.

This doesn't make any sense, it's a threaded fastener. Either it's tight and doesn't move, or it's loose and does. If it moves with a significant amount of drag then maybe part of the index pin got sheared off and is stuck in the threads? Or your barrelsmith is clueless and used threadlocker on a barrel extension or something like that.

ok, lets see if i can clear it up... when in a vise, the barrel will move about an inch back and forth, but only if i use a tool on a muzzle device. i cannot move the barrel with my hands.

here's an awesome late-breaking update: the gunsmith just got back to me. he said to mail it to him and he will fix it up. here's to hoping and praying that it can be fixed easily!

If the barrel is in a vise, and you torque on the muzzle device, how does that have anything to do with the barrel extension?
ok, now i think i understand our confusion. i know the extension moves because when the barrel was still attached to the upper with the barrel nut installed, that's when the extension started letting the barrel to move. the extension gave a "pop" when it let go, i thought it was the muzzle break, but it was not.

Or are you still torquing on the muzzle device with the upper in a receiver block?!?!
no, i took the barrel off the upper, but after the incident. that probably was my biggest mistake. i tried to take off the muzzle device without using a barrel vise. i was able to get the break off putting the barrel in a vise wrapped with a bike inner tube with wood on both sides of the vise. it came off pretty easily after that.

I would have serious reservations about any gunsmith fixing it up in a sufficient way if it's actually a loose barrel extension.
i am relieved he is willing to look at it. i guess i'll have to wait to see what he says.

Please post some photos so I can try to figure out what is happening. If you're still doing all this with a receiver block you probably just sheared off the index pin and/or trashed the upper receiver (maybe both).
the upper looks to be fine. i will try to get some pics tomorrow if i have time. i will try to show how much movement there is by marking the barrel with before/after pics.

my responses in red.

if i'm still confusing people, i apologize.

now i understand why your avatar looks the way it does.

Posted: 2/7/2016 1:17:39 AM EDT

[#26]

Quote History

Quoted:
There are apparently many large-scale manufacturers who precut chambers to particular thread locations, with matching specifically threaded extensions so that the barrel itself is all done then the extension is attached. During that process the torque values will likely be somewhat variable as it all depends on exactly how well they can hold their machining specifications. I strongly suspect this process being out of whack is the genesis of all the loose barrel extension experiences over the last several years.

View Quote

I'm not even remotely large scale and this is how I chamber all my barrels. It's a perfectly acceptable process and produces consistent results, but I also take the time and attention to keep all related tolerances to .0005 or less.

Fixing a removed/loose extension on a standard barrel (not nitride or chrome lined) is an easy fix, just not nessicarily a cheap one unless everything lines up correctly after torquing.

Not to nitpick but there's a difference between 'brake' and 'break' . In this case both apply

Posted: 2/7/2016 1:35:36 AM EDT

[#27]

Quote History

Quoted:
ok, now i think i understand our confusion. i know the extension moves because when the barrel was still attached to the upper with the barrel nut installed, that's when the extension started letting the barrel to move. the extension gave a "pop" when it let go, i thought it was the muzzle break, but it was not.

View Quote

What you describe would be the same if the index pin sheared and allowed the barrel + barrel extension to rotate.