[ARCHIVED THREAD] - Gas Block/Tube Question

Posted: 4/23/2011 10:56:24 AM EDT

I am building a Carbine M4 upper and just purchased the barrel below in the link:

http://www.brownells.com/.aspx/pid=29320/Product/M4_STRIPPED_BARREL

I am using a DD M4 7.0 Rail and was wondering if the length of the carbine gas tube would allow for a low profile block to be installed under the rail to hide it or if I needed to get a different gas block that extends past the rail? Thanks for your help.

Posted: 4/23/2011 1:48:43 PM EDT

[#1]

Quoted:
I am building a Carbine M4 upper and just purchased the barrel below in the link:

http://www.brownells.com/.aspx/pid=29320/Product/M4_STRIPPED_BARREL

I am using a DD M4 7.0 Rail and was wondering if the length of the carbine gas tube would allow for a low profile block to be installed under the rail to hide it or if I needed to get a different gas block that extends past the rail? Thanks for your help.

With a carbine length gas system you will need at least a 9'' rail to cover a LPGB a 10'' or 12'' rail will also work. The barrel that you purchased has a carbine length gas system so you have to use a carbine length gas tube.
What LPGB did you purchase?

Posted: 4/23/2011 2:02:12 PM EDT

[#2]

I have not purchased one yet. I was waiting for a response first. I think now I am going to get on with a rail on top of it though since it has to extended past the DD rail.

Posted: 4/23/2011 2:23:48 PM EDT

[#3]

The 7'' carbine DD rail will work with a front sight base but if you are wanting to use a low profile gas block and have it located under the rail the 7''will not work.
Is this your first ar build?

FSB

LPGB

Posted: 4/23/2011 4:08:50 PM EDT

[#4]

Yeah first upper build. I think I am going to go with a YHM single rail gas block and mount it just forward of the DD rail. Would that work? I do not want a front sight post. Just a folding front sight like the Troy battle sight. All my parts have not come in yet so I can check the fit just now.

Posted: 4/23/2011 4:20:57 PM EDT

[#5]

Quoted:
Yeah first upper build. I think I am going to go with a YHM single rail gas block and mount it just forward of the DD rail. Would that work? I do not want a front sight post. Just a folding front sight like the Troy battle sight. All my parts have not come in yet so I can check the fit just now.

Is this the gas block you are referring to? If this is the GB the DD 7'' rail is what you need.
What series of DD rail do you have? Is the rail a DD m4 series free float.