AR-15 handguard question

[T.Lex]

Ok. So, I have a budget-build AR-15 (documented in a different thread) and the upper came with a non-railed handguard.

Like this:

It is a DoubleStar free float, rifle length handguard that screws on.

In retrospect, I should have gotten what I really wanted. Rails.

So, now I'm trying to figure out the best solution. Really, the goal is to get BUIS on this at a reasonable price.

My main question is whether there is any standardization with regard to how the free float handguards mount. I know there isn't "true" standardization, in that some of them have proprietary systems to increase the rigidity. I'm more interested in whether the "drop in"/budget will allow me to simply screw on or otherwise use the existing mounting mechanism.

Or do I just gamble. Alas, I'm not much of a gambler.

TIA

 

[xM3RC1L3SS1x]

If I am understanding this correctly the free-float has a different mount system then the drop-ins that utilize the standard barrel nut. There are manufacturers that make short length picatinny rails that mount to free-float handguards so you can mount a BUIS to it. Or you could swap out the handguard for a railed free-float handguard from the same manufacturer. I would call them first though to make sure that the mounting hardware is the same. If not it shouldn't be hard at all to swap it out. I hope this helps.

 

[Leo]

The poster above is correct, to change that handguard you will need to remove the barrel nut and use the barrel nut that comes with the new barrel. There always seems to be just enough difference to not be standardized. I had one where the outer threads were the same so I though all was golden, until I realized that the new float tube needed a much thicker one to tighten against. I really like the handguard on your new upper, I would not mind having one like it.

 

[NyleRN]

That handguard probably has it's own proprietary nut. There's several railed free float forarms that will mount to a standard $7 barrel nut

 

[NyleRN]

Also, you mentioned this is a budget build. To keep costs down just buy a standard barrel nut and pick up a UTG super slim modular. They have gotten excellent reviews and are around $100

 

[T.Lex]

I really like the handguard on your new upper, I would not mind having one like it.

Wanna trade? PM me if you want to work something out.

I can see the utility of the one I have. In fact, I entertained ideas of testing a rattlecan camo idea on it. But, I think I would do better to just get a railed handguard that I like.

 

[rvb]

I have a budget-build AR-15 ... and the upper came with a non-railed handguard.

Really, the goal is to get BUIS on this at a reasonable price.

I'm more interested in whether the "drop in"/budget will allow me to simply screw on or otherwise use the existing mounting mechanism.

It sounds like you didn't build the upper. You are going to have to essentially re-barrel that upper (remove the handguard, flash hider, gas tube, gas block, barrel nut). That requires tools (eg vice block, barrel nut wrench) or a trip to a gunsmith. If you are running irons on the handguard, you want something that mounts extremely solid or you will forever be chasing a zero. "cheapest" may cost you more in the long run...

-rvb

 

[T.Lex]

It sounds like you didn't build the upper. You are going to have to essentially re-barrel that upper (remove the handguard, flash hider, gas tube, gas block, barrel nut). That requires tools (eg vice block, barrel nut wrench) or a trip to a gunsmith. If you are running irons on the handguard, you want something that mounts extremely solid or you will forever be chasing a zero. "cheapest" may cost you more in the long run...

-rvb

Yeah, that's kinda where I'm ending up. The upper came assembled.

I have access to the tools - and don't mind getting some tools myself (like the barrel nut wrench thing) that I might use more frequently.

I'd like to avoid messing with the "mechanical" things, like the gas block.

So, that leaves me getting another complete upper with what I want on it.

 

[twostepadin]

If the low-pro gas block is the all-threaded kind. It is honestly as easy as taking out the BCG, unscrewing muzzle device, unscrewing gas block all-threads and sliding off the barrel. It'll go back to where it is supposed to with that barrel profile. Now, if its pinned? its hamma time. lol

As the above posters have said plenty of nice hand guards run off the standard barrel nut. I.E. Fortis Rev.

Good luck!

 

[wsenefeld]

I'd like to avoid messing with the "mechanical" things, like the gas block.

If switching handguard you'll also be switching barrel nuts as I highly doubt you'll be finding one with an identical barrel nut. Being that you'd have to remove the barrel nut you'll also have to remove the gas tube but it would be easier to remove the gas block (which isn't mechanical) and slide the gas tube off with it. This is a very easy process. Watch a couple YouTube videos and you'll be doing it in your sleep.

 

[krd]

Double Star sells railed handgaurds. Call and see if it uses the same barrel nut as the tube.

 

[NyleRN]

Is double star even in business still? I don't see anyone selling their products anymore

 

[SmileDocHill]

Another thing to consider...I found out the hard way that back up iron sights mounted on lite weight free float tube are NOT for precision shooting. Granted I was using a sling which ads pressure to the rail but at a KD appleseed (out to 400yds) it got really tricky when I had to standardize the same amount of sling pressure so the flexing of the tube was the same. I have 2 AR's with free float tubes, one is very rigid but no rails (have to use an optic) and the other has rails.
At the last 1500 I made a point to look at every upper I could get my hands on that had a free float tube on it. I could take one hand and squeeze the barrel toward the rail with little effort on most all of them. The only ones I could not are the ones that are thick and heavy and really more for varmint guns.
My pref., should I build again is to have the front sight mounted on the barrel, let the tube flex, I just don't like it when it takes the front sight with it.

 

[rvb]

Another thing to consider...I found out the hard way that back up iron sights mounted on lite weight free float tube are NOT for precision shooting. Granted I was using a sling which ads pressure to the rail but at a KD appleseed (out to 400yds) it got really tricky when I had to standardize the same amount of sling pressure so the flexing of the tube was the same. I have 2 AR's with free float tubes, one is very rigid but no rails (have to use an optic) and the other has rails.
At the last 1500 I made a point to look at every upper I could get my hands on that had a free float tube on it. I could take one hand and squeeze the barrel toward the rail with little effort on most all of them. The only ones I could not are the ones that are thick and heavy and really more for varmint guns.
My pref., should I build again is to have the front sight mounted on the barrel, let the tube flex, I just don't like it when it takes the front sight with it.

Just squeezing the barrel/handguard together doesn't always tell the whole story. Barrels flex pretty easy too, esp thinner ones. It's hard to bend a 2" aluminum tube. Most of the flex you see in handguards is in the mount. You can verify some of this w. a straightedge as you pinch the barrel/handguards and see which is giving. In General, IMO, handguards w. bigger barrel nuts giving more surface contact to the handguard are the most rigid (noveske, JP, Geisselle, bcm, dd). I had a set of troy/VTAC handguards I ripped off as the mount was just trash, I could move the front end 1/4" w. Very little pressure when pinching to the barrel, and if pressed hard into sandbags could make them touch the gas block...I wasn't bending the tube but the mount just couldn't hold things solid. I put a JP tube on and now if I pinch the bbl/HG together it's mostly the barrel that moves. All that said, you are 100% right that for best results irons should be on the barrel. With a good handguard, you can at least get decent results with irons. W. Junk handguards, as I said above, you'll forever be chasing a zero.

-rvb

edit: example of bad HG flexing at the nut

 

[T.Lex]

Good point SDH and rvb.

For me, the BUIS are truly a backup. I can hardly see 400 yards nowadays without an optic, let alone shoot that far with any accuracy.

As I progress along AR modding, I may look at trying one of those barrel-clamp front sights. That is probably the best solution, but it seems hard to find one that isn't also the gas block.