Mid Length Handguard on Carbine Gas AR15?

WheelGunRealGun · January 29, 2019, 05:38 PM

I'm wanting to put a Daniel Defense Omega 9.0 Quad Rail on a Colt 6920 OEM 2 (the one with the low profile gas block). I see that Daniel Defense says the 9" Omega was meant for midlength. Could I run into any problems putting it on a carbine length w/ a low-pro gas block? Such as the gas block hitting the rail during firing or something? Has anyone done this?

Basically I want to get a rail that completely covers the low-pro gas block so it's not just sitting there outside the end of the rail looking silly.

Mobuck · January 29, 2019, 06:46 PM

"Such as the gas block hitting the rail during firing or something?"

That will NOT happen unless something comes loose. Depending on how the FF attaches, it may or may not be possible to install the handguard over an already in place gas block and tube.

sevt_chevelle · January 29, 2019, 07:17 PM

All my rails, bcm and Midwest extend past over the gas block no problem.

FrankenMauser · January 29, 2019, 07:41 PM

I cover nearly all of my gas blocks (FF tube extends over the GB).

Some combinations of gas block and free float tube will have interference issues. I don't know anything about the DD Omega, or what the factory Colt GB dimensions are. So, I can't offer advice on that specific combination.

But when I run into problems, I turn to the Troy low profile gas blocks. They'll fit inside almost anything - including the .875" version inside Midwest Industries SSK (super slim) free float tubes.

Just make sure you have at least 0.050" or so clearance around the GB, and it should be fine.

Scorch · January 31, 2019, 02:08 AM

The only gas blocks I see issues with are the type with a rail on top. If you get a low-profile gas block, I have never seen one interfere with even the smallest diameter fore end rail. Of course, I only see a couple dozen or so a month.

ms6852 · January 31, 2019, 02:28 AM

You may have a timing issue since it is made for a mid length instead of a carbine length rifle. The problem will be with the dwell time which could cause jams and cycling issues.

Mobuck · January 31, 2019, 07:10 AM

"You may have a timing issue since it is made for a mid length instead of a carbine length rifle. The problem will be with the dwell time which could cause jams and cycling issues."

OP is asking about putting a mid-length hand guard over the carbine length gasblock.

stagpanther · January 31, 2019, 11:44 AM

I personally prefer my gas blocks to be right at the end of the rail.

FrankenMauser · January 31, 2019, 12:58 PM

Quote:

The only gas blocks I see issues with are the type with a rail on top. If you get a low-profile gas block, I have never seen one interfere with even the smallest diameter fore end rail. Of course, I only see a couple dozen or so a month.

Midwest Industries SSK and SSM (now "Slim Line"?) tubes interfere with most set-screw gas blocks on the market, and I am not aware of a single clamp-on gas block that will fit. (There probably is at least one. I just haven't seen one that works.)
I've also seen or read of issues arising with AR Stoner, Leapers, Classic Firearms, GunTec, AimSports, and more free float tubes. -Generally cheap stuff, or Chinese knock-offs of the MI SSK/SSM series.

Contact is almost universally at the bottom of the gas block, on the set screw boss.

kymasabe · February 1, 2019, 09:18 PM

I have carbine and midlength gas rifles with 12.5. 13.5 and 15 inch long free float handguard. As long as the handguard clears the low profile gas block with no interference, you can run any length you want.
Next...have you shot a rifle with quad rail before? They're often sharp edges and like trying to hang onto a cheese grater.

Mobuck · February 2, 2019, 07:21 AM

"They're often sharp edges and like trying to hang onto a cheese grater."

+1 on that. The only way to actually USE the "railed HG" is to wrap it with "vet wrap" which then gets sticky or full of sand, dirt, or ??
Those "rails" also eat up any piece of equipment they lay against while being hauled/carried.

stagpanther · February 2, 2019, 09:36 AM

cheap plastic/rubber rail covers also can do the job.

WheelGunRealGun · February 4, 2019, 06:55 PM

Quote:

Next...have you shot a rifle with quad rail before? They're often sharp edges and like trying to hang onto a cheese grater.

Yes, I have for years. To be honest I don't buy into the current fad of ultralight and thin tubes with attachment slots. I have never experienced discomfort with a quad rail, especially with rail covers. I also prefer the looks, though that's a secondary factor.

To each their own, it's just not for me.

January 29, 2019, 05:38 PM	#1
WheelGunRealGun Senior Member Join Date: January 5, 2012 Posts: 126	Mid Length Handguard on Carbine Gas AR15? I'm wanting to put a Daniel Defense Omega 9.0 Quad Rail on a Colt 6920 OEM 2 (the one with the low profile gas block). I see that Daniel Defense says the 9" Omega was meant for midlength. Could I run into any problems putting it on a carbine length w/ a low-pro gas block? Such as the gas block hitting the rail during firing or something? Has anyone done this? Basically I want to get a rail that completely covers the low-pro gas block so it's not just sitting there outside the end of the rail looking silly.

January 29, 2019, 07:41 PM	#4
FrankenMauser Senior Member Join Date: August 25, 2008 Location: In the valley above the plain Posts: 13,424	I cover nearly all of my gas blocks (FF tube extends over the GB). Some combinations of gas block and free float tube will have interference issues. I don't know anything about the DD Omega, or what the factory Colt GB dimensions are. So, I can't offer advice on that specific combination. But when I run into problems, I turn to the Troy low profile gas blocks. They'll fit inside almost anything - including the .875" version inside Midwest Industries SSK (super slim) free float tubes. Just make sure you have at least 0.050" or so clearance around the GB, and it should be fine. __________________ Don't even try it. It's even worse than the internet would lead you to believe.

January 31, 2019, 02:08 AM	#5
Scorch Senior Member Join Date: February 13, 2006 Location: Washington state Posts: 15,248	The only gas blocks I see issues with are the type with a rail on top. If you get a low-profile gas block, I have never seen one interfere with even the smallest diameter fore end rail. Of course, I only see a couple dozen or so a month. __________________ Never try to educate someone who resists knowledge at all costs. But what do I know? Summit Arms Services

January 31, 2019, 02:28 AM	#6
ms6852 Senior Member Join Date: April 3, 2010 Location: Texas Posts: 1,394	You may have a timing issue since it is made for a mid length instead of a carbine length rifle. The problem will be with the dwell time which could cause jams and cycling issues. __________________ ONLY TWO DEFINING FORCES HAVE GIVEN UP THEIR LIVES FOR YOU. ONE IS JESUS CHRIST FOR YOUR SOUL AND THE OTHER IS THE AMERICAN SOLDIER FOR YOUR FREEDOM.

January 31, 2019, 11:44 AM	#8
stagpanther Senior Member Join Date: March 2, 2014 Posts: 11,789	I personally prefer my gas blocks to be right at the end of the rail. __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!*

January 29, 2019, 06:46 PM	#2
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	"Such as the gas block hitting the rail during firing or something?" That will NOT happen unless something comes loose. Depending on how the FF attaches, it may or may not be possible to install the handguard over an already in place gas block and tube.

January 29, 2019, 07:17 PM	#3
sevt_chevelle Senior Member Join Date: April 13, 2013 Posts: 324	All my rails, bcm and Midwest extend past over the gas block no problem.

January 31, 2019, 07:10 AM	#7
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	"You may have a timing issue since it is made for a mid length instead of a carbine length rifle. The problem will be with the dwell time which could cause jams and cycling issues." OP is asking about putting a mid-length hand guard over the carbine length gasblock.

February 1, 2019, 09:18 PM	#10
kymasabe Senior Member Join Date: June 10, 2005 Location: SW Florida Posts: 2,747	I have carbine and midlength gas rifles with 12.5. 13.5 and 15 inch long free float handguard. As long as the handguard clears the low profile gas block with no interference, you can run any length you want. Next...have you shot a rifle with quad rail before? They're often sharp edges and like trying to hang onto a cheese grater. __________________ God's creatures big and small, eat them one, eat them all.

February 2, 2019, 07:21 AM	#11
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	"They're often sharp edges and like trying to hang onto a cheese grater." +1 on that. The only way to actually USE the "railed HG" is to wrap it with "vet wrap" which then gets sticky or full of sand, dirt, or ?? Those "rails" also eat up any piece of equipment they lay against while being hauled/carried.

February 2, 2019, 09:36 AM	#12
stagpanther Senior Member Join Date: March 2, 2014 Posts: 11,789	cheap plastic/rubber rail covers also can do the job. __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!*