rifle length Magpul MOE's on an 18" barrel...

brian923 · March 18, 2011, 07:42 PM

Hey guys, long story short... I had an AR in 223 and got a new bison 6.8spc barrel. Instead of waiting, I swapped barrels. Now, I want to rebuild the 223, and was looking at getting some of the MOE handgaurds for the 6.8 and putting the free float back on the 223. I would like to use rifle length handgaurds on the 6.8, but the gas block is a mid length. Is there any way to make this work, or no... Thanks, brian.

Technosavant · March 18, 2011, 08:05 PM

The only way to make it work would be to have a FSB pinned on at the rifle length position with the appropriate handguard cap. And that depends on your existing gas block being low profile and fitting under the handguards (no idea if they might). Basically, you'd end up doing what Bushmaster does with their Dissipator uppers (with some minor differences in length, but the same concept).

So in other words, probably not. At least, not without the expense of a gunsmith.

brian923 · March 18, 2011, 08:20 PM

That's what I was thinking would have to be done, but I didn't know exactly. Sounds like a new free float tube would be cheaper. Thanks, brian.

Jim243 · March 18, 2011, 08:44 PM

Do you have the front sight on the mid-length barrel. If the answer is yes then UTG has an extended hand guard that might fit. Or you could use a DD hand guard with the rasied rail. They are pretty cool looking but expensive.

Jim

http://www.cheaperthandirt.com/ARR157-7.html

http://www.cheaperthandirt.com/ItemD...px?sku=ARR-146

http://www.cheaperthandirt.com/ItemD...x?sku=ARR-3302

tirod · March 19, 2011, 10:05 AM

You don't need a gunsmith. There are different ways to do it, mainly come up with a lopro gas block for under the handguard. That can be a dremeled off GI already there, which eliminates all the difficult pinning rework. Then add a clamp on FSB at the rifle position with new cap. Modifying the issue FSB is lots of work, and the tools, drill bits, etc are about the same cost as the $89-$95 clamp on when done. Two choices I've found are the National Match set screw type, or the slick JP adjustable front sight base.

The point is moving a .750 front sight base and getting a good grip on the forward part of the barrel, usually .700 or less, isn't a real easy thing to do. I'm right in the middle of it, it takes good tooling to work on forged steel. A nitrided barrel just adds to the difficulty level, there won't be any pinning.

If you have the cash flow, that JP is really nice...

March 18, 2011, 07:42 PM	#1
brian923 Senior Member Join Date: September 6, 2009 Posts: 183	rifle length Magpul MOE's on an 18" barrel... Hey guys, long story short... I had an AR in 223 and got a new bison 6.8spc barrel. Instead of waiting, I swapped barrels. Now, I want to rebuild the 223, and was looking at getting some of the MOE handgaurds for the 6.8 and putting the free float back on the 223. I would like to use rifle length handgaurds on the 6.8, but the gas block is a mid length. Is there any way to make this work, or no... Thanks, brian.

March 18, 2011, 08:44 PM	#4
Jim243 Senior Member Join Date: January 6, 2009 Location: Just off Route 66 Posts: 5,067	Do you have the front sight on the mid-length barrel. If the answer is yes then UTG has an extended hand guard that might fit. Or you could use a DD hand guard with the rasied rail. They are pretty cool looking but expensive. Jim http://www.cheaperthandirt.com/ARR157-7.html http://www.cheaperthandirt.com/ItemD...px?sku=ARR-146 http://www.cheaperthandirt.com/ItemD...x?sku=ARR-3302 Last edited by Jim243; March 18, 2011 at 08:59 PM.

March 18, 2011, 08:05 PM	#2
Technosavant Senior Member Join Date: May 29, 2007 Location: St. Louis, MO area Posts: 4,040	The only way to make it work would be to have a FSB pinned on at the rifle length position with the appropriate handguard cap. And that depends on your existing gas block being low profile and fitting under the handguards (no idea if they might). Basically, you'd end up doing what Bushmaster does with their Dissipator uppers (with some minor differences in length, but the same concept). So in other words, probably not. At least, not without the expense of a gunsmith.

March 18, 2011, 08:20 PM	#3
brian923 Senior Member Join Date: September 6, 2009 Posts: 183	That's what I was thinking would have to be done, but I didn't know exactly. Sounds like a new free float tube would be cheaper. Thanks, brian.

March 19, 2011, 10:05 AM	#5
tirod Junior member Join Date: January 21, 2009 Posts: 1,672	You don't need a gunsmith. There are different ways to do it, mainly come up with a lopro gas block for under the handguard. That can be a dremeled off GI already there, which eliminates all the difficult pinning rework. Then add a clamp on FSB at the rifle position with new cap. Modifying the issue FSB is lots of work, and the tools, drill bits, etc are about the same cost as the $89-$95 clamp on when done. Two choices I've found are the National Match set screw type, or the slick JP adjustable front sight base. The point is moving a .750 front sight base and getting a good grip on the forward part of the barrel, usually .700 or less, isn't a real easy thing to do. I'm right in the middle of it, it takes good tooling to work on forged steel. A nitrided barrel just adds to the difficulty level, there won't be any pinning. If you have the cash flow, that JP is really nice...