AR-15 Handguard Upgrade

[Weatherby5]

Good evening,

I am wanting a little bit of advice on the upgrading of the handguard on my AR setup. I am trying to get away from the A2 front sight, so I uninstalled it, so I currently have the round front retaining ring, a carbine length gas tube, a clamping (low profile) gas block and I just purchased a Magpul MOE Mid-length handguard. Am I missing something? Should this work?

 

[Demi-human]

I am no expert, but I am sure that a carbine length hand guard must be employed with a carbine length gas tube, if one was going to use the pressed metal ring that rests against the gas block and the delta ring, which compresses the whole assembly together. Were it a free floating type it wouldn't matter so much.

Welcome to The High Road! A Clean, Well Lighted Establishment!

 

[Varminterror]

Not gonna work. The MOE clamshell handguard will not fit in your carbine. 9” handguard in a 7” gap...

 

[Driftertank]

Yeah, only way to run a longer handguard on a short gas system is to run a low-pro gas block under a free-float guard. Sorry...

 

[Driftertank]

Yeah, only way to run a longer handguard on a short gas system is to run a low-pro gas block under a free-float guard. Sorry...

Eta: or a dissipator setup. But i think that generally requires a special barrel...

 

[MistWolf]

1) Shave your original front sight to make it into a low profile gas block and re-pin it into place with the round handguard cap.

2) Get the Magpul carbine length Slimline handguards.

If you try to use the handguard cap with the aftermarket low profile gas block, chances are the gas block won't line up with gas port.

Trying to replace a front sight block with something different can get complicated. Keep it simple and just shave the front sight.

 

[Weatherby5]

Not gonna work. The MOE clamshell handguard will not fit in your carbine. 9” handguard in a 7” gap...

So if I purchased the carbine length hand guard I would be okay?

1) Shave your original front sight to make it into a low profile gas block and re-pin it into place with the round handguard cap.

2) Get the Magpul carbine length Slimline handguards.

If you try to use the handguard cap with the aftermarket low profile gas block, chances are the gas block won't line up with gas port.

Trying to replace a front sight block with something different can get complicated. Keep it simple and just shave the front sight.

The whole purpose of buying an aftermarket clamp-on gas block is so I wouldn't have to shave down the A2 front sight.

So from what I'm gathering from you guys, I just need a carbine length hand guard instead of a mid length and I should be fine?

 

[Varminterror]

Yup

 

[MistWolf]

The whole purpose of suggesting shaving the front sight block is to avoid using a clamp on gas block. Clamp on gas blocks have a tendency to break their clamping screws.

Shaving the front sight base gives you the most reliable low profile gas block possible, assuming it's the pinned version.

 

[Captains1911]

What you are missing, from what it sounds like, is a front sight.

 

[Varminterror]

Clamp on gas blocks work. I’ve installed a few hundred of them on customer rifles, and my own, in the last ~18yrs, assuredly running hundreds on hundreds of thousands of rounds.

You have a clam-shell set up, so you either have to fully swap over to a free float set up, OR you have to use a carbine length handguard.

Dissipator set ups have absolutely NOTHING to do with this issue. That advice is nothing but confusing. A “dissipator” carbine is a 16” barrel with a mid-length gas system - that’s not a “special barrel,” but it’s also not what our OP owns.

 

[Charlie98]

A “dissipator” carbine is a 16” barrel with a mid-length gas system - that’s not a “special barrel,” but it’s also not what our OP owns.

Thought a Dissipator was a 16" barrel with a full length gas system? A 16" with a mid-length is just that... a mid-length system.

 

[Varminterror]

Depends who's selling it. The design intent is to run a lower port pressure than carbine length. Not black magic. Either way, it's NOT what the OP owns.

 

[MistWolf]

Clamp on gas blocks work.

They do work, but they also have a tendency to break the clamping screws. The screws are bent and stretched at the gap as they are tightened. This concentrates the stress on the screws at one place. When the screws break, it's almost always at this place.

 

[Varminterror]

I can absolutely understand that THEORY. In literally hundreds of them I've personally installed, owned, serviced, etc, I have NOT seen any "tendency" for breakage or bending in actual application. YMMV, but personally, the whole "clamp on's break" is a lot more internet sensation than it is actual, real-world problem.

 

[MistWolf]

It's always worse (or better) on the internet than it is in real life. I've seen many clamp on screws break and not just on AR gas blocks. I've talked to knowledgeable guys I trust who have seen first hand, clamp on gas block screws break. Clamp screws almost always break in the same spot. It's inherent flaw with the design. But it's your money, it's your rifle.

 

[Driftertank]

Clamp on gas blocks work. I’ve installed a few hundred of them on customer rifles, and my own, in the last ~18yrs, assuredly running hundreds on hundreds of thousands of rounds.

You have a clam-shell set up, so you either have to fully swap over to a free float set up, OR you have to use a carbine length handguard.

Dissipator set ups have absolutely NOTHING to do with this issue. That advice is nothing but confusing. A “dissipator” carbine is a 16” barrel with a mid-length gas system - that’s not a “special barrel,” but it’s also not what our OP owns.

I meant in terms of some of the commercial "dissipator" setups that a few companies have offered where they basically hide a carbine or middy low-pro under old-school handguards with a dummy sight post to retain the handguards and give longer sight radius...i remember seeing someone offering "dissipator" barrels some time ago (brownells?) and couldnt remember if it had a double-humped barrel for the gas tap and dummy sight post.