Armalite AR 10 handguard replacement, accuracy and torque

[pre64hunter]

I have an Armalite AR 10 flat top I believe it's just called the Defensive Sporting Rifle. The handguard is the standard military type with a delta ring and the barrel has a gas block with the little short picatinny rail. I am thinking of replacing the handguard with a free float tube type. Midway sells a simple EGW and Armalite sells a little nicer one for around $80. Will a free float forearm show any improvement in accuracy?

Next question is torque, when replacing the delta ring with a barrel nut the torque specs are fairly generous. I replaced one on a Colt AR 15 a long time ago and basically, it didn't seem to have much room for forgiveness. You tightened the barrel nut snug and then tightened it some more till the gas tube hole lined up, the torque was what it was. I mean the previous hole would have been too loose and the next hole was out of the question. It was very tight, it was over torqued getting to the hole that lined up.

Last question is the gas block. Can the gas block just be left as is? It'll probably have to be removed and reinstalled to replace the handguard and just leave out the handguard cap that holds the factory handguard in place. Any problem removing the flash suppressor?

I've had this for 10 years or so and I'm finally getting around to shooting it. By now you can tell I'm not really into AR type weapons. I'm not interested in attaching accessories and don't care for the long rail type handguards, my main interest is accuracy.

 

[Magnumite]

Typically the barrel nut is tightened to a minimum torque then turned to align the gas tube without exceeding a maximum value. That said, on a DPMS which I had the factory barrel nut torque was TIGHT!

 

[DaemonAssassin]

I have an Armalite AR 10 flat top I believe it's just called the Defensive Sporting Rifle. The handguard is the standard military type with a delta ring and the barrel has a gas block with the little short picatinny rail. I am thinking of replacing the handguard with a free float tube type. Midway sells a simple EGW and Armalite sells a little nicer one for around $80. Will a free float forearm show any improvement in accuracy?

Next question is torque, when replacing the delta ring with a barrel nut the torque specs are fairly generous. I replaced one on a Colt AR 15 a long time ago and basically, it didn't seem to have much room for forgiveness. You tightened the barrel nut snug and then tightened it some more till the gas tube hole lined up, the torque was what it was. I mean the previous hole would have been too loose and the next hole was out of the question. It was very tight, it was over torqued getting to the hole that lined up.

Last question is the gas block. Can the gas block just be left as is? It'll probably have to be removed and reinstalled to replace the handguard and just leave out the handguard cap that holds the factory handguard in place. Any problem removing the flash suppressor?

I've had this for 10 years or so and I'm finally getting around to shooting it. By now you can tell I'm not really into AR type weapons. I'm not interested in attaching accessories and don't care for the long rail type handguards, my main interest is accuracy.

The biggest problem you will face in replacing the handguard is if the new handguard barrel nut is compatible with the Armalite pattern AR-10.

A free floated handguard will give you better accuracy, because it removes the random stress/flex on the barrel when you are holding it or shooting it off of sandbags.

Another thing you can do to get a bit more accuracy out of that rifle is to lap the upper receiver face and possibly bed the barrel into the upper.

If the gas block is not a standard low profile gas block that is held in place by set screws, then it might be easier to replace the whole barrel assembly or take it to Lord Chad for him to work on.

You can remove the flash hider, but you will need the correct tool to get it off and then you will have to replace the crush washer with a new crush washer, when putting the flash hider back on.

On the AR-15 the GI barrel nut torque values were 40-80 ft/lbs. I think those are max values for the AR-10 GI barrel nut also. You will need a armorers wrench, a torque wrench, and a socket breaker bar for that.

 

[pre64hunter]

I got the factory barrel nut off and as magnumight said, it was TIGHT. Had to use two heavy vises and custom fit vise blocks both on the upper and barrel, and breaker bar with a 30" extension. Didn't wreck anything.
Armalite says torque 45-90ft/lbs. for the AR 10. Used a PRI barrel nut wrench from Midway that held good, I was afraid the wrench would break but it is super tough. The EGW free float tube threads fits the Armalite.
It was difficult to find a simple inexpensive free float handguard for the AR 10. Everything AR 15 is no problem but the AR 10 is a red heron.
Thanks for the help everyone.

 

[DaemonAssassin]

I got the factory barrel nut off and as magnumight said, it was TIGHT. Had to use two heavy vises and custom fit vise blocks both on the upper and barrel, and breaker bar with a 30" extension. Didn't wreck anything.
Armalite says torque 45-90ft/lbs. for the AR 10. Used a PRI barrel nut wrench from Midway that held good, I was afraid the wrench would break but it is super tough. The EGW free float tube threads fits the Armalite.
It was difficult to find a simple inexpensive free float handguard for the AR 10. Everything AR 15 is no problem but the AR 10 is a red heron.
Thanks for the help everyone.

Sweet Jesus....

Did you bother to get a reaction rod of any kind to do this?

 

[pre64hunter]

Sweet Jesus....

Did you bother to get a reaction rod of any kind to do this?

Yes, tried that first then added the blocks for more support.
Yes, sweet Jesus! I probably won't be doing it again.
I only posting this to share my experience, live and learn.
I soaked the nut in Kroil for over a week too.

 

[Magnumite]

For those seeking an inexpensive handguard. This looks a little large in diameter and I don’t know how reliable but…

AR 308 HANDGUARD MODULAR 15IN TACFIRE

AR 308 HANDGUARD MODULAR 15IN TACFIRE

www.cdnnsports.com

 

[Worsley]

This is super easy to install, bomb proof, and affordable.

CMR 7.62 MLOK Rail (11.5in - 15in)

Centurion's patented 7.62 MLOK CMR rail system is a lightweight, rugged, one piece, free float hand guard that offers a continuous 12 oâclock rail.

centurionarms.com