AR15.Com Archives
 AR-10 BARREL CHANGING VISE BLOCK
kattman  [Member]
10/15/2008 8:57:38 AM
What are you guys using for AR-10 upper receiver vise block(s) for barrel changing or installation? Will a DPMS 308 unit work with th Armalite AR-10? Pics would be appreciated. Thanks.

Kattman from Michigan
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mrraley  [Moderator]
10/15/2008 11:07:39 AM
I have no idea on the DPMS .308 block, but if you call ArmaLite they should be able to help and get you a part number.

I got mine when I went through the armorers' course.
Desert_AIP  [Team Member]
10/15/2008 11:24:32 AM
You can use barrel blocks instead of a receiver block.
I use them for all my builds because there is less stress on the aluminum receiver when torquing the barrel nut.
This is the "old school" way of installing the barrel.
leo6223  [Member]
10/15/2008 2:51:37 PM
If it's for an A4 you can just turn it sideways and use two wood blocks
Slash  [Dealer]
10/15/2008 7:59:28 PM

Originally Posted By Desert_AIP:
You can use barrel blocks instead of a receiver block.
I use them for all my builds because there is less stress on the aluminum receiver when torquing the barrel nut.
This is the "old school" way of installing the barrel.




Barrel blocks are only appropriate for doing work on muzzle devices, never for re-barreling. The correct tool for the job is a good set of receiver blocks, available from ArmaLite:






Barrel blocks put rotational stress on the alignment pin and the slot in the receiver, which were not designed to be exposed to this type of force. I've seen receivers destroyed by WECSOGers using the wrong tool for the job.


DnPRK  [Team Member]
10/15/2008 8:59:13 PM
Call Armalite and get the receiver blocks Slash showed in his post. The Armalite barrel nut is tight! I tried to remove the barrel nut using the DPMS claw and permanently twisted the receiver (door won't close). Put the same receiver in the Armalite blocks and had the nut off in <10 seconds. The proper tools make a big difference.
Halfcocked  [Team Member]
10/15/2008 9:32:53 PM
I use two pieces of pine slatt for my flat top.

Clamp the fucker in a vice and go at it.
G3SG1MAN  [Team Member]
10/15/2008 9:41:28 PM
ex1615
Firebird69  [Member]
10/16/2008 10:19:06 AM
Bushmaster vice works good.

Desert_AIP  [Team Member]
10/16/2008 11:24:37 AM

Originally Posted By Slash:

Originally Posted By Desert_AIP:
You can use barrel blocks instead of a receiver block.
I use them for all my builds because there is less stress on the aluminum receiver when torquing the barrel nut.
This is the "old school" way of installing the barrel.




Barrel blocks are only appropriate for doing work on muzzle devices, never for re-barreling. The correct tool for the job is a good set of receiver blocks, available from ArmaLite:

i4.photobucket.com/albums/y102/slash1969/Gun%20Pics/AR10ReceiverBlocks1.jpg

i4.photobucket.com/albums/y102/slash1969/Gun%20Pics/AR10ReceiverBlocks2.jpg


Barrel blocks put rotational stress on the alignment pin and the slot in the receiver, which were not designed to be exposed to this type of force. I've seen receivers destroyed by WECSOGers using the wrong tool for the job.




Hmmm...It seems military armorers would disagree.

TM9-1005-319-23



I'm not sure I understand your concerns with the indexing pin.
With barrel blocks you are effetively screwing a nut onto the receiver and drawing it into the barrel extension.
With a receiver fixture, you are placing all that torque on the aluminum lugs for the pivot and takedown pins.
Even with a clamshell fixture there is the entire weight of the barrel being supported at the receiver as you are torquing the nut. This could elongate the receiver/barrel interface (even if it is just a tiny bit).
With barrel blocks, the receiver (a lot lighter) is supported by the barrel.

13-F-COLT  [Team Member]
10/16/2008 4:32:08 PM

Originally Posted By Desert_AIP:

I'm not sure I understand your concerns with the indexing pin.
With barrel blocks you are effetively screwing a nut onto the receiver and drawing it into the barrel extension.
With a receiver fixture, you are placing all that torque on the aluminum lugs for the pivot and takedown pins.
Even with a clamshell fixture there is the entire weight of the barrel being supported at the receiver as you are torquing the nut. This could elongate the receiver/barrel interface (even if it is just a tiny bit).
With barrel blocks, the receiver (a lot lighter) is supported by the barrel.



umm the upper is supporting the entire weight of the barrel because that is what it does.
some of mine with very heavy barrels. i have never even heard of that being a concern or
causing elongation of anything.

what i have seen happen many, many, times are uppers with cracked index pin slots,
some were unsalvageable, because barrel blocks were used and the upper took the
rotational stress from torquing. something it was not designed to do.

the "which vise blocks to use" issue has been beat to death so many times. regardless
of whats in a manual, it has been proven that it is better to clamp the upper.
TaylorWSO  [Life Member]
10/16/2008 6:36:29 PM
Vice blocks are the best, the barrel will hang on the upper receiver when you remove the barrel blocks, so I don't see the concern of it hanging it on their when using receiver blocks.

The DoD has many stupid ass regs/guidance that I would never put my personal stuff through. That TM/TO also recommends using a pry bar to hold the FSB if the barrel twists in the barrel block.

There will be torque from the nut, it can either be:

1. On the threads, through the receiver, to the receiver blocks, OR

2. On the threads, to the index pin, through the barrel to the barrel blocks. This route will have all force concentrated on a small pin pressing against the aluminum receiver. Bad news IMO.
Slash  [Dealer]
10/16/2008 11:01:35 PM

Originally Posted By Desert_AIP:

Originally Posted By Slash:

Originally Posted By Desert_AIP:
You can use barrel blocks instead of a receiver block.
I use them for all my builds because there is less stress on the aluminum receiver when torquing the barrel nut.
This is the "old school" way of installing the barrel.

Barrel blocks are only appropriate for doing work on muzzle devices, never for re-barreling. The correct tool for the job is a good set of receiver blocks, available from ArmaLite:

i4.photobucket.com/albums/y102/slash1969/Gun%20Pics/AR10ReceiverBlocks1.jpg

i4.photobucket.com/albums/y102/slash1969/Gun%20Pics/AR10ReceiverBlocks2.jpg


Barrel blocks put rotational stress on the alignment pin and the slot in the receiver, which were not designed to be exposed to this type of force. I've seen receivers destroyed by WECSOGers using the wrong tool for the job.

Hmmm...It seems military armorers would disagree.
TM9-1005-319-23
i175.photobucket.com/albums/w135/Desert_AIP/TMBarrel.jpg
I'm not sure I understand your concerns with the indexing pin.
With barrel blocks you are effetively screwing a nut onto the receiver and drawing it into the barrel extension.
With a receiver fixture, you are placing all that torque on the aluminum lugs for the pivot and takedown pins.
Even with a clamshell fixture there is the entire weight of the barrel being supported at the receiver as you are torquing the nut. This could elongate the receiver/barrel interface (even if it is just a tiny bit).
With barrel blocks, the receiver (a lot lighter) is supported by the barrel.


The .mil is not known for always providing the best tools (or training) for the job.

This issue is quite simple if you think about it. When tightening a nut and bolt you use two wrenches, right? One on the nut and another on the bolt. If you try to tighten a nut without a wrench on the bolt head what happens? The bolt turns. If you don't use a receiver block, all of the torque you put on the barrel nut is transmitted to the alignment notch via the indexing pin.

With the proper receiver blocks (as shown in my photos above) there is ZERO torque on the pivot/takedown lugs. The pin-style blocks are useless for anything but cleaning/maintenance IMO.

There is less stress on the barrel-receiver interface with a new barrel hanging off it in a receiver block than there is when a fully assembled rifle is fired from a bipod. I'll wager that a VFG multiplies that stress several times. Do you think that ArmaLite would manufacture and sell receiver block if assembling an upper with them was really a hazard?

Again, I have personally seen receivers damaged by people who used barrel blocks and 'field expedient' receiver blocks, AKA chunks of wood. I've never seen or even heard of a receiver that was 'elongated' with properly designed receiver blocks. Good tools can be expensive, but the right tool for the job is priceless.

kattman  [Member]
10/17/2008 4:52:55 AM
From Slash's first post with pics-----I'm getting/using the Armalite's/

Thanks--again----Slash

Kattman from Michigan
Desert_AIP  [Team Member]
10/17/2008 1:10:13 PM

Originally Posted By Slash:

Originally Posted By Desert_AIP:
I'm not sure I understand your concerns with the indexing pin.


The .mil is not known for always providing the best tools (or training) for the job.

This issue is quite simple if you think about it. When tightening a nut and bolt you use two wrenches, right? One on the nut and another on the bolt. If you try to tighten a nut without a wrench on the bolt head what happens? The bolt turns. If you don't use a receiver block, all of the torque you put on the barrel nut is transmitted to the alignment notch via the indexing pin.

With the proper receiver blocks (as shown in my photos above) there is ZERO torque on the pivot/takedown lugs. The pin-style blocks are useless for anything but cleaning/maintenance IMO.

There is less stress on the barrel-receiver interface with a new barrel hanging off it in a receiver block than there is when a fully assembled rifle is fired from a bipod. I'll wager that a VFG multiplies that stress several times. Do you think that ArmaLite would manufacture and sell receiver block if assembling an upper with them was really a hazard?

Again, I have personally seen receivers damaged by people who used barrel blocks and 'field expedient' receiver blocks, AKA chunks of wood. I've never seen or even heard of a receiver that was 'elongated' with properly designed receiver blocks. Good tools can be expensive, but the right tool for the job is priceless.



Thanks for the info Slash, I'll have to re-look at this. Hmmm
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