Sheared off barrel extension pin.

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[ARCHIVED THREAD] - Sheared off barrel extension pin.

Posted: 8/21/2014 1:10:54 PM EDT

I have a spare in hand but the material left is too shallow to use an easy out.

Posted: 8/21/2014 1:49:53 PM EDT

[#1]

How?

Posted: 8/21/2014 1:53:54 PM EDT

[#2]

Moronic gunsmith put about 10x as much locktite as was necessary to attach the barrel nut about a year ago, so I took it to another gunsmith to get it off to put a different rail on who used a Geissele rod instead of a receiver vice. So the pin sheared before the but broke free
ETA missed info

Posted: 8/21/2014 2:03:37 PM EDT

[#3]

Good to know.

Punt.

Posted: 8/21/2014 2:26:34 PM EDT

[#4]

Loctite has no business on a barrel nut. And reaction rods aren't the right choice for torquing barrel nuts particularly tough ones, but I repeat myself...

The pins are just press fit into the barrel extension. If you can't pull it out any other way, perhaps drill a (small) hole into the middle of the pin and then start a tiny sheet metal screw into the hole to get a grip on it. Understand that there's only about 1/8 inch or so of pin that's inside the barrel extension so definitely don't drill too deep.

Posted: 8/21/2014 4:27:03 PM EDT

[#5]

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Quoted:
Moronic gunsmith put about 10x as much locktite as was necessary to attach the barrel nut about a year ago, so I took it to another gunsmith to get it off to put a different rail on who used a Geissele rod instead of a receiver vice. So the pin sheared before the but broke free
ETA missed info

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He shouldnt have used any at all.

Posted: 8/21/2014 5:17:39 PM EDT

[#6]

I used a 7/64 drill bit to get my sheared pin out. Slowly drill into the pin a little bit on forward, then reverse the rotation so the bit will bite into the pin. I was able to spin what was left of the pin up and out.

Posted: 8/21/2014 5:28:23 PM EDT

[#7]

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Quoted:
I used a 7/64 drill bit to get my sheared pin out. Slowly drill into the pin a little bit on forward, then reverse the rotation so the bit will bite into the pin. I was able to spin what was left of the pin up and out.

<a href="http://smg.photobucket.com/user/squidkid/media/DSCN4113_zps094094bd.jpg.html" target="_blank">http://img.photobucket.com/albums/v332/squidkid/DSCN4113_zps094094bd.jpg</a>

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Fantastic. Thanks mate

Posted: 8/22/2014 6:29:20 AM EDT

[#8]

Yep, the reaction rod is still racking up at least one index pin a month.

Sure, Loctite made the situation a lot worse but the reaction rod sealed the deal.

Posted: 8/22/2014 11:36:04 AM EDT

[#9]

Two this month so far. Mine was Tuesday night. Yeah...............

Posted: 8/22/2014 2:40:05 PM EDT

[#10]

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Quoted:
Two this month so far. Mine was Tuesday night. Yeah...............

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Makes sense, the more popular the reaction rod gets this is bound to happen more often.

Posted: 8/22/2014 2:52:14 PM EDT

[#11]

Loctite on a barrel nut?

I've always used AeroShell 33MS and haven't had one come loose yet (and I own a shooting school and my training AR's see a LOT of student use).

Am I missing something?

Posted: 8/22/2014 3:32:40 PM EDT

[#12]

Posted: 8/22/2014 6:57:56 PM EDT

[#13]

Quote History

Quoted:
Loctite on a barrel nut?

I've always used AeroShell 33MS and haven't had one come loose yet (and I own a shooting school and my training AR's see a LOT of student use).

Am I missing something?

View Quote

Just clueless gunsmiths being clueless.

Posted: 8/25/2014 1:53:42 PM EDT

[#14]

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Quoted:

Just clueless gunsmiths being clueless.

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Quoted:

Quoted:
Loctite on a barrel nut?

I've always used AeroShell 33MS and haven't had one come loose yet (and I own a shooting school and my training AR's see a LOT of student use).

Am I missing something?

Just clueless gunsmiths being clueless.

Not only charging for their expertise, but getting away with it, again.

Posted: 8/25/2014 2:03:46 PM EDT

[#15]

I have been making and owning AR15s since 1996, and I thought I had at least HEARD of most everything. But I thought the indexing pin was part of the extension. Okay, its not. But WTH is a 'reaction rod'?

ETA: Okay, went back and studied the thread again - it must be a device to use instead of the proper block/vise? That's why I don't know what it is - I wouldn't use it.

Posted: 8/25/2014 2:17:02 PM EDT

[#16]

http://geissele.com/reaction-rod.html

Posted: 8/25/2014 8:00:13 PM EDT

[#17]

Quote History

Quoted:
Two this month so far. Mine was Tuesday night. Yeah...............

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I am having brain fade about why this happens, how the forces shear pins. How do the forces through using a reaction rod cause this to happen. I have only used receiver blocks but have considered a reaction rod for muzzle brakes and barrel work to avoid the twist on a receiver but I am probably overthinking this.
Gamma, if you read this I hope you comment.

Posted: 8/26/2014 5:34:04 AM EDT

[#18]

Quote History

Quoted:

I am having brain fade about why this happens, how the forces shear pins. How do the forces through using a reaction rod cause this to happen. I have only used receiver blocks but have considered a reaction rod for muzzle brakes and barrel work to avoid the twist on a receiver but I am probably overthinking this.
Gamma, if you read this I hope you comment.

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Quoted:

Quoted:
Two this month so far. Mine was Tuesday night. Yeah...............

I am having brain fade about why this happens, how the forces shear pins. How do the forces through using a reaction rod cause this to happen. I have only used receiver blocks but have considered a reaction rod for muzzle brakes and barrel work to avoid the twist on a receiver but I am probably overthinking this.
Gamma, if you read this I hope you comment.

The Reaction Rod holds at the barrel extension lugs and stops the barrel from turning in the receiver but torque applied to the barrel nut rotates the upper receiver against the index pin. The index pin will shear depending on how stuck the barrel nut is to the upper receiver threads.

The vast majority of the people on this forum will say this can't happen despite the fact that this happens once or twice a month around here with pictures to prove it.

Posted: 8/26/2014 5:36:08 AM EDT

[#19]

Thank you, sir.

Posted: 8/26/2014 5:42:37 AM EDT

[#20]

Quote History

Quoted:

The Reaction Rod holds at the barrel extension lugs and stops the barrel from turning in the receiver but torque applied to the barrel nut rotates the upper receiver against the index pin. The index pin will shear depending on how stuck the barrel nut is to the upper receiver threads.

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Quoted:

Quoted:
Two this month so far. Mine was Tuesday night. Yeah...............

I am having brain fade about why this happens, how the forces shear pins. How do the forces through using a reaction rod cause this to happen. I have only used receiver blocks but have considered a reaction rod for muzzle brakes and barrel work to avoid the twist on a receiver but I am probably overthinking this.
Gamma, if you read this I hope you comment.

The Reaction Rod holds at the barrel extension lugs and stops the barrel from turning in the receiver but torque applied to the barrel nut rotates the upper receiver against the index pin. The index pin will shear depending on how stuck the barrel nut is to the upper receiver threads.

So clamping the barrel in a vise (as in the picture above, presumable from the tech manual) would result in the same problem.
I guess with a stubborn barrel nut you risk a problem no matter what you do, reaction rod/barrel in vise shear the pin, receiver block bend your receiver. Maybe try both at the same time.

Posted: 8/26/2014 5:47:26 AM EDT

[#21]

Quote History

Quoted:

So clamping the barrel in a vise (as in the picture above, presumable from the tech manual) would result in the same problem.
I guess with a stubborn barrel nut you risk a problem no matter what you do, reaction rod/barrel in vise shear the pin, receiver block bend your receiver. Maybe try both at the same time.

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Quoted:

Quoted:
Two this month so far. Mine was Tuesday night. Yeah...............

I am having brain fade about why this happens, how the forces shear pins. How do the forces through using a reaction rod cause this to happen. I have only used receiver blocks but have considered a reaction rod for muzzle brakes and barrel work to avoid the twist on a receiver but I am probably overthinking this.
Gamma, if you read this I hope you comment.

The Reaction Rod holds at the barrel extension lugs and stops the barrel from turning in the receiver but torque applied to the barrel nut rotates the upper receiver against the index pin. The index pin will shear depending on how stuck the barrel nut is to the upper receiver threads.

So clamping the barrel in a vise (as in the picture above, presumable from the tech manual) would result in the same problem.
I guess with a stubborn barrel nut you risk a problem no matter what you do, reaction rod/barrel in vise shear the pin, receiver block bend your receiver. Maybe try both at the same time.

Yes. Though your best bet is the clam shell upper receiver vise blocks.

Also, with the barrel blocks you stand a chance of loosening your barrel from the barrel extension.

Posted: 8/26/2014 1:39:57 PM EDT

[#22]

So, on the barrel nut, he used the exact opposite of the material he was supposed to use then?

Hey Frank, I need some very specific grease. Screw it, let's just use the strongest glue we have handy. It's wet too, right?

Posted: 8/27/2014 11:30:02 AM EDT

[#23]

Standard barrel nut, just moly lube and go.

But on DCM float tubes, due the amount of sling torque that the tube and barrel nut will see than can cause both to spin, I will use locktite on all the threads. Come yearly rebuilds of such NM rifles, I already know that the works has been loctite'd so they will not sling torque spin, so a quick hit with a torque to break down the loctite bond, and the parts spin off with ease.

Posted: 8/27/2014 4:29:48 PM EDT

[#24]

So I am getting ready to buy something to install a new free float handguard, what do I need a reactiion rod or clamshell vise clamps

Posted: 8/27/2014 4:49:13 PM EDT

[#25]

I know of 2 different types of upper receiver supports. The clam shell and the insert types. The clam shell does not fit every upper receiver but the insert style does. The link to the clam shell type also shows the lower receiver block. I have and use both.

Upper receiver insert style

Clamshell style

Posted: 8/27/2014 5:25:32 PM EDT

[#26]

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Quoted:
I know of 2 different types of upper receiver supports. The clam shell and the insert types. The clam shell does not fit every upper receiver but the insert style does. The link to the clam shell type also shows the lower receiver block. I have and use both.

Upper receiver insert style

Clamshell style

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I would avoid the vise block in the first link. Those pin style blocks damage upper receivers all the time when trying to use them for barrel installation or removal.

The only safe way to use the pin style vise blocks for barrel installation or removal is when they are combined with a block that goes over the top rail and then this gets clamped sideways in a vise.

Like in this link. > https://www.youtube.com/watch?v=7xJXP3wY6x4&list=UUkCUNbusbwJOIIxg_feoyFg

Posted: 8/27/2014 5:56:04 PM EDT

[#27]

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Quoted:

I would avoid the vise block in the first link. Those pin style blocks damage upper receivers all the time when trying to use them for barrel installation or removal.

The only safe way to use the pin style vise blocks for barrel installation or removal is when they are combined with a block that goes over the top rail and then this gets clamped sideways in a vise.

Like in this link. > https://www.youtube.com/watch?v=7xJXP3wY6x4&list=UUkCUNbusbwJOIIxg_feoyFg

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Quoted:

Quoted:
I know of 2 different types of upper receiver supports. The clam shell and the insert types. The clam shell does not fit every upper receiver but the insert style does. The link to the clam shell type also shows the lower receiver block. I have and use both.

Upper receiver insert style

Clamshell style

I would avoid the vise block in the first link. Those pin style blocks damage upper receivers all the time when trying to use them for barrel installation or removal.

The only safe way to use the pin style vise blocks for barrel installation or removal is when they are combined with a block that goes over the top rail and then this gets clamped sideways in a vise.

Like in this link. > https://www.youtube.com/watch?v=7xJXP3wY6x4&list=UUkCUNbusbwJOIIxg_feoyFg

The DPMS Panther Claw is what is used by DPMS during assembly of their factory rifles. Probably hundreds of thousands if not more rifle they have produced, and you don't hear about bent receivers. The blocks that have no insert and only have have push pins to hold the upper are the ones that allow the upper to flex and bend. I have used the Panther Claw for over a decade, for over a hundred assembly/disassemblies easily, including some with serious barrel nut torque... never a problem. Ever. The upper is supported from the inside with that block. With that said, I like the clam shell blocks as well; I have used them before too.