AR school 103: Handguard History

[Skribs]

I was wondering if someone could school me on some of the purpose behind some of the AR-15 handguards. I can understand some of the newer modular handguards, but some (to me at least) just look ugly and very uncomfortable.

I could be using the wrong terms here, but I see 5 main types:

1) The M16A1 style handguard, which I don't really see used on modern rifles. Why did that fall out of favor?
2) The M16A2 style handguard, which appears to be slightly tapered towards the front. Why was this chosen over the A1?
3) Nowadays the most common mall ninja handguard is the quad rail, or at least a railed handguard. I understand the allure here, as I wanted one for a while.
4) The magpul MOE, or other non-standard modular handguards. I actually think I like the look of this.
5) What I call the "pipe" handguard, these basically look like a metal tube that someone thought "I think my AR barrel and gas tube will fit in there, might as well use it." What is the purpose of these? The A2 style looks so much better IMHO.

Anyway, I'm just trying to find out mainly why the older style of handguard (#1) fell out of favor and why #5 even exists. It is a biased/abrasive question but I'm hoping for honest answers.

 

[Bartholomew Roberts]

The older style has both left and right halves so if a part breaks, you have to replace it with the appropriate half. The A2 style uses the same handguard on top and bottom, so it is logistically simpler to maintain a lot of rifles. I'm not sure if that was the official reasoning behind adopting the A2 handguards; but it is certainly one of the effects.

 

[HDCamel]

I believe that A2 handguards (in addition to simplifying logistics) are also less brittle than A1 handguards and I think they also have improved heat shields.

 

[Jon_Snow]

I can't comment on the history, but the reason that the "pipe" handguards exist is that they allow the barrel to (almost) free-float. Typical AR handguards are held in place by being sandwiched between a leaf spring on the receiver and a plate on the gas block, about 2/3rds down the barrel. This means that changes in pressure on the handguard (ie from hand position, resting it on something or using a sling) can affect POI and therefore degrade accuracy. The free-float "pipe" handguards are screwed onto the receiver and don't touch the barrel at all.

I say they allow the barrel to almost free-float because the gas block is still out there. I've seen rifles where people have a free-float handguard and then attach a sling to the gas block. They sling up and wonder why their zero keeps moving.

ETA: I know you didn't specifically ask but the idea behind the magpul MOE is to create an inexpensive replacement for the standard handguards that works well with the magpul style hold; grabbing the handgaurd at the gas block and pulling backwards. It's supposed to allow you to drive the gun for faster transitions, btu I've not tried it myself. (Not enough time to add 3-gun on top of USPSA and silhouette).

 

[Skribs]

So why couldn't you have a pipe for freefloating and make it look better?

I thought the MOE was for a light, cheap customizable option. It seems to be what I would need instead of a quad rail.

 

[Ro1911]

They switch to the A2 because its only one piece that works for both top and bottom, the A1's were a right and left piece non interchangeable. The created problems at the armory when you had a broken handguard you'd have to order a whole new set unless you had a spare of the one that broke. In short the A2 is cheaper and easier from an armorers standpoint.

 

[Welding Rod]

So why couldn't you have a pipe for freefloating and make it look better?

You could, there are. But the "pipe" style is inexpensive, rugged, does the job, and is ergonomic. I have one on a few of my ARs and them alot.

 

[Justin]

So why couldn't you have a pipe for freefloating and make it look better?

Not sure what's wrong with the way they look, but the tubular hand guards, in addition to the advantages of free-floating that were mentioned by Jon, also have another advantage in that they're highly modular. Instead of using a quad rail fore end, you only need to attach pieces of rail where you need them, which ends up saving you some weight.

They're also more comfortable to shoot. Some models of quad rail have sharp edges and can be downright uncomfortable to grab. The tubular free float tubes don't have nearly as many edges.

I say they allow the barrel to almost free-float because the gas block is still out there. I've seen rifles where people have a free-float handguard and then attach a sling to the gas block. They sling up and wonder why their zero keeps moving.

That's a misinformed user, not really a problem with the choice of hand guard.

I thought the MOE was for a light, cheap customizable option. It seems to be what I would need instead of a quad rail.

The MOE hand guards are designed to be an after-market replacement for standard A1- or A2-style hand guards. You can attach rail to them, but they don't offer the advantage of allowing you to free-float the barrel.

 

[cfullgraf]

So why couldn't you have a pipe for freefloating and make it look better?

Beauty is in the eye of the beholder. With the variety of options available for the AR style rifles, one should be able to find something that peaks their fancy.

I have a long, heavy barrel, varmint AR with a plain, free float, tubular hand guard, no frills, no modularity, very functional for the task the rifle is assembled for.

But not everyone would like these plain hand guard and that is just fine with me.

 

[MachIVshooter]

1) The M16A1 style handguard, which I don't really see used on modern rifles. Why did that fall out of favor?

Ro1911 covered the economic side. The practical side is heat; The A1 handguard has no top heat shield, allowing heat from the barrel and gas tube to vent upward uninhibited, which isn't comfortable.

2) The M16A2 style handguard, which appears to be slightly tapered towards the front. Why was this chosen over the A1?

See #1

3) Nowadays the most common mall ninja handguard is the quad rail, or at least a railed handguard. I understand the allure here, as I wanted one for a while.

Try attaching a forward grip, bi pod or light without rails. It can be done, but the rails make it a snap. They also have a look that some people like (I do). I dunno, you tell me which looks better on this BCM 12.5 I just got:

Stock w/A2 hand guards:



With free floated 13" quad rail:



Also the benefit of being able to put my hand anywhere I want.

4) The magpul MOE, or other non-standard modular handguards. I actually think I like the look of this.

The MOE hand guard is more ergonomic than A2 style, readily accepts the MOE rail or other MOE accessories, and doesn't break the bank. It also looks better in certain applications. I chose it for my Pistol:



Of course, the way I set it up on the pistol, I can't really make use of the finger tang up front (unless I feel like getting burned)

5) What I call the "pipe" handguard, these basically look like a metal tube that someone thought "I think my AR barrel and gas tube will fit in there, might as well use it." What is the purpose of these? The A2 style looks so much better IMHO.

The purpose of the free float tube has been covered. As for aesthetics, what do you want? There are a number of different styles, from the most basic "piece of pipe" look you dislike to somewhat decorative, themed, countoured, etc.

 

[hq]

So why couldn't you have a pipe for freefloating and make it look better?

Yes and no. My favorites are small diameter free float tubes that have provisions to attach stock A2 handguards on them. I've been looking for even smaller ones that would accept triangular A1 handguards. After experimenting with all kinds of mall ninja gadgets, I've gone back to basics and prefer OEM looks.

 

[Bovice]

The free float tube's objective is to eliminate vibrational nodes in the barrel. The barrel itself will oscillate when a shot is fired. The stiffer the barrel and the fewer nodes it has makes a more repeatable POI. Adding nodes is like adding another "hump" in the waveform.

 

[Skribs]

I thought the free float was simply so that you don't flex the barrel when applying pressure to it.

 

[MachIVshooter]

I thought the free float was simply so that you don't flex the barrel when applying pressure to it.

It's that as well. Anything putting pressure on the barrel will alter the harmonics, whether it's your hands or something attached to the barrel. Standard handguards have a solid mechanical connection between receiver and sight base, so even if you're not touching them, they are still applying pressure to the barrel, and they still affect the movement of the barrel during firing. Free float tubes eliminate both problem. Now, gas tubes should be free floating themselves, though not all manufacturers are careful about this when torquing the barrel nut, so check that; You should be able to wiggle the tube just a tad. I've seen more than a few rifles that had the scallops on the nut misaligned, causing the tube to be in firm contact with both the barrel nut and the receiver.

 

[68wj]

So why couldn't you have a pipe for freefloating and make it look better?

Like that:


Or that:


Looks are subjective, but I think what you are asking is for a freefloating "pipe" that is more than just a round piece of metal. This is the norm of the modular freefloated forearms that give the flexibility of the quadrail without the bulk and weight. Just add a rail where you want it.