[knutsen24]

So about a year ago I made a deal with a buddy for an AR (in pieces). I did some work for him and got a barrel, complete upper, stock and the guts for the lower. Anyway, I picked up a lower and put it all together and everything works great.

Now, my question is about the gas tube coming out of the barrel. My AR has a standard hand guard on it, approx. 9". Well, I just did a trade with another guy and got a grip pod and he threw in a couple other things. One of which is a longer quad rail. Here's my question.... Since this new quad rail goes past where the gas tube exits the barrel, am I even going to be able to use it? Is there any part that I can use to keep the barrel and gas tube in it's original position and still use the quad rail? After all, it was free so I'd like to use it.

Thanks in advance!

 

[Quentin]

Well you've got to give more specifics and pictures would be good. But if you're talking about a standard FSB, they can be cut down and still function as a lo-pro gas block with a longer free float rail. Again, that's just a generality, depends on what you've got.

 

[ktmboyz]

By standard hand guards do you mean the plastic two piece? if so and you are planning one changing to a free float quad rail you will need to change the barrel nut to the threaded type for the q/r to thread onto. Also you will need to get a low frofile gas block that will fit under the q/rail.. pretty sure on this but Im sure others will be along to clarify

 

[knutsen24]

Thanks guys! I will post a couple pictures later today. The Q/R is not threaded, so I guess that means its not a free float. I think. I'll have to look again.

 

[knutsen24]

Here's a couple more pics.

 

[knutsen24]

Is this what I need? I must need something else to secure the front end of the Q/R too.

http://www.brownells.com/.aspx/cid=.../Products/All/search=AR_low_profile_gas_block

 

[Sgt_Skrb_25]

Ya the low pro gas block will work for you. If you intend on using a free float rail, you don't want to attach anything up front. It will defeat the purpose of the free float. The advantage of the free float is that you don't mess with the harmonics I the barrel up front. The rail will all connect up by the upper receiver only. Hope that helps.

 

[EW1066]

Judging by the pictures, what you have there is NOT a free float hand guard. Also it will not work on your rifle because it is designed to work with a Rifle length gas system. Your rifle has a carbine length gas system and is therefore not compatible. The scope riser could be useful if you have a scope that requires more clearance for the objective lens. It looks to be too tall to allow for co-witness of a red dot. I honestly can't say for sure since your BUIS is in the down position. Maybe you could trade that hand guard and scope riser for a flip up front sight. That would at least allow you to aim the weapon.

EDUB

 

[knutsen24]

I thought I could get away with a low profile gas block and slide my current gas block forward to accept the front of the quad rail. I currently have a scope and front & rear BUS they just aren't in the pictures. Thanks for the help fellas. I'll let you know how it turns out.

 

[EW1066]

I thought I could get away with a low profile gas block and slide my current gas block forward to accept the front of the quad rail. I currently have a scope and front & rear BUS they just aren't in the pictures. Thanks for the help fellas. I'll let you know how it turns out.

Please take some time to familiarize yourself with the function of every part on the weapon before you try to start making modifications. Moving the gas block is not an option without moving the gas port , which you are probably not capable of doing. If you had tried to do that(move the gas block), it would have ended in a very dangerous situation for you. Again, PLEASE educate yourself on the function of every part of the rifle. If this were airsoft you could make mods with no worries other than wasting a few dollars. This aint airsoft and serious injury could result from ill-conceived/uninformed modifications.

Bottom line Have fun but be very careful

EDUB

 

[jjfuller1]

i say try to tade the handgaurd for extra mags or ammo. and then shoot the rifle the way it is.

 

[knutsen24]

EW, I appreciate your input and warning of malfunctions. On the other hand, I am not a child that plays with airsoft toys. If you re-read my last comment you will see that I mentioned I was going to use a low profile gas block where it should go and slide my current gas block forward to accept the end of the quad rail. The reason for this is because my current gas block has a small rail and top to use but mainly because it has the hand guard cap as well.

Thanks again.

 

[Sgt_Skrb_25]

Are you planing on mounting a sight on the gas block with a rail? It's not necessary to keep that block on of it serves no purpose, just extra weight, and interference on the harmonics of the barrel. Not sure what you using this rifle for but if you want a thumbtack driver keep it a true free float and don't attach anything to the barrel that doesn't need to be there. A free float will not attach to what ever hand guard adapter is on that block anyways.

 

[sniper762]

EW is spot on. carbine barrels, quad rails, handguards and gas tubes are not compatable with full length rifles.

 

[Quentin]

I thought I could get away with a low profile gas block and slide my current gas block forward to accept the front of the quad rail. I currently have a scope and front & rear BUS they just aren't in the pictures. Thanks for the help fellas. I'll let you know how it turns out.

I have to agree with EW, I think you're asking for trouble. Why not sell the upper as it is and buy another that will work with that rail (or also sell the rail and get exactly what you want). In the long run you'll come out ahead.

 

[EW1066]

Just to clarify. The airsoft comment was not ment as a stab at you. I was only trying to remind you that there could be dire consequences for bad ,or ill advised, modifications. I see that you have many hand guns. That being said I see alot of people start with AR's and are infatuated by the modularity. As a result they sometimes believe that nothing is outside the relm of possibility. To some extent this is true. The reality of the situation, however, is that somethings cannot or should not be done. Is your idea possible? Sure! But what's the point? Are you trying to save money? Or are you simply trying to make the best out of a bad trade? At this point you should write it off to experience. Go invest some money in a front sight and ammo and go shoot the gun. Find out what you NEED and then make modifications.

EDUB

 

[SWBMOAMP2691]

EW, I appreciate your input and warning of malfunctions. On the other hand, I am not a child that plays with airsoft toys. If you re-read my last comment you will see that I mentioned I was going to use a low profile gas block where it should go and slide my current gas block forward to accept the end of the quad rail. The reason for this is because my current gas block has a small rail and top to use but mainly because it has the hand guard cap as well.

Thanks again.

Just my two cents, but I don't think moving your current gas block farther down the barrel would be a viable option while using a lowpro gas block for the carbine length gas system. What I would do is sell/ trade the quad rail you have and invest in getting the lowpro gas block and using a midlength free float quad rail. Make the quad rail as flush with the upper receiver as possible and then you can use rail mounted sights on the end of the quad rail. Additionally you could get a hold of a carbine length quad rail instead (free float or not) and utilize the existing gas block rail to mount a front sight. I think the latter would be more cost and weight efficient but the first option would increase your sight radius and real estate on your quad rail. having two gas blocks with only one functioning? I would consider that unnecessary when there are better options. Just my opinion, good luck and good shooting.

 

[lilbailnick]

It's clear the answer in past threads is there! You have a carbine length gas system and doing a modification to accept a mid-length hand guard is absolutely point less to me(to each his own). As others have stated sell the hand guards and buy some goodies that accommodate and fit as is! Vltor sell a free float "like" hand guards that will tie into delta ring and also the top rail of your upper. They have a few different sizes that would give you that longer hand guard look that you're going for...good luck