AR-15 Workbench: How to Upgrade Your Handguard

A longer guard can be fitted with more accessories and offers more real estate to grip the rifle. Some handguards feature alternative attachment systems (M-LOK, Picatinny, etc.), and some reduce the amount of heat transferred from the barrel. Others are designed to be as lightweight as possible, while still others are designed to be practically bulletproof. Or, you might want to change your handguard just because you want a cooler-looking long gun.

Whatever your reason, it’s worth doing the job yourself. Like working on cars or home appliances, there’s something satisfying about modifying your own rifle, and the process is relatively painless with a few simple tools.

How to Choose an Aftermarket Handguard

There are hundreds of handguards on the market, so choosing the right one for you requires a clear understanding of your priorities.

One of the first considerations should be the length. There was a time when handguards were divided by carbine, mid-length, and rifle-length varieties. Some manufacturers still use those terms, but many offer handguards in one- or two-inch increments. That way, you can get a guard exactly the length you need for your rifle.

I prefer a handguard to be just a little shorter than where the threads begin on the muzzle (usually about 1.5 inches less than the length of the barrel). That lets me grip the rifle as far forward as I can without worrying about touching a screaming hot barrel. But it also ensures I can attach a suppressor or other muzzle device without the handguard interfering.

However, some prefer a shorter handguard to save weight, while others install a handguard that extends beyond the muzzle. This setup allows a suppressor to be installed under the handguard as long as the guard is wider than the gun muffler. I get why people do this (it looks pretty slick), but it also strikes me as a bit impractical (what if you want to shoot the gun without a suppressor?).

You can reduce the gun’s overall weight by opting for a slim, lightweight handguard, or you can increase your attachment options by going with a quad rail or something with M-LOK slots at 3, 6, and 9 o’clock.

Even more important than how a handguard looks on the outside is how it mounts to the rifle. There are basically two mounting systems: drop-in and free float. You can still buy drop-in handguards that work with A2-style front sights and replace the cheap plastic guard that comes with bargain-bin AR-15s. These units are usually polymer, and they’re cheap and easy to install.

These days, however, free-float handguards are far more common. These guards don’t touch the barrel, which increases the accuracy of the rifle. Aluminum guards are also more durable and allow accessories to be attached more securely.

But they’re also more expensive and difficult to install. While you might spend as little as $30 on a drop-in handguard, you’ll likely spend over $100 on an aluminum free-float. The Midwest Industries T-Series quad rail I used for this how-to was $195, which I admit is a pretty penny for a bit of aluminum.

If you go with a free-float, be sure the barrel nut doesn’t require tuning or allow slippage. The barrel nut is, as you may have guessed, the nut that threads onto the front of the receiver and secures the barrel. Each handguard comes with its own (usually proprietary) barrel nut. Some require tuning with shims to allow the gas tube to fit through one of the holes and into the receiver. This is the kind of nut that was on the AR-15 I used in this article. Stay away from those. They’re generally a pain in the butt, and there are better options out there.

Also, be sure that the handguard attaches securely to the barrel nut. Sometimes, a free-float handguard can slowly work its way off the nut over the course of thousands of rounds. You can avoid this annoyance by purchasing a handguard that uses a no-slip system, so do your research before pulling the trigger.

Installation Procedure

Once you’ve selected your new handguard, I recommend also purchasing a vise block for the upper receiver. I’ve done this job without one, but the vise block makes it exponentially easier and reduces the odds of bending or scratching the upper receiver.

Step 1: Remove the Old Handguard

I can’t offer much advice here, since I don’t know what kind of handguard is currently installed on your rifle. But mine required removing eight Torx head screws and sliding the guard off the barrel nut. If you purchased a complete rifle, the guard might require some convincing; just be sure you’ve removed all the fasteners first.

Step 2: Remove the Muzzle Device (If You Have One)

As annoying as it is, you’ll need to remove a few more things before you’ll be able to unscrew the old barrel nut. The first is the muzzle device. Hopefully, the device on your rifle wasn’t installed with a compound that requires a special procedure to remove. I previously installed this one with Rocksett, which just needs to be soaked in hot water for about 15 minutes. If you’re wrenching on the muzzle device and it’s not budging, it might be worth getting in touch with the manufacturer.

Step 3: Remove the Gas Block and Tube

Once the muzzle device is removed, you can slide off the gas block and tube. Your gas block might be affixed with a different system than mine was, but it will likely be some combination of pins and set screws. Use a hammer and punch to remove any pins, unscrew the set screws, and slide the block and tube off the muzzle end of the rifle.

Note: You don’t have to remove the gas tube from the gas block unless you want to inspect and clean it.

Step 4: Unscrew the Old Barrel Nut

This is where things might get tricky. Every barrel nut is different, and some require a special tool to remove. Most can be removed with an AR-15 armorer’s wrench or a regular crescent wrench. If neither of those do the trick, you might have to get creative or contact the manufacturer. Fortunately, I was able to remove mine with an armorer’s wrench without too much trouble.

Step 5: Install the New Barrel Nut

Your new handguard will come with a barrel nut and, if necessary, a wrench. Follow the manufacturer’s installation instructions here. Some require the nut to be torqued to a certain weight, while others allow for a range. Also, don’t skip the anti-seize grease. That’ll make removing the barrel nut much easier if you decide to remove it again.

In my case, Midwest Industries included a wrench head that can be affixed to a torque wrench, and they recommend torquing the barrel nut to 40 foot-pounds.

Step 6: Reinstall Gas Block and Muzzle Device

Reverse the procedure to reinstall the gas block and tube first, then the muzzle device. Be sure the gas block is aligned before tightening the set screws.

Step 7: Install the New Handguard

Midwest Industries has developed an ingenious system that allows the handguard to be aligned and secured using a torque plate. This torque plate fits into the bottom of the handguard, and a tab slides into a groove on the barrel nut. This ensures that the handguard doesn’t slide forward, and it keeps the guard secure and aligned with the upper receiver. It also allows the guard to use a barrel nut that doesn’t require tuning, which makes the entire process so much easier.

To install, just insert the plate and torque the two screws to 40 inch-pounds.

Last Shot

Put the rifle back together, confirm it’s unloaded, and do a function check. Inspect your work for anything that looks strange or misaligned, and make sure the handguard doesn’t move or wiggle. If it doesn’t, you should be good to go.

As I noted in a previous AR-15 Workbench, swapping out a handguard isn’t as easy as changing a pistol grip or stock. But with the right tools, a little know-how, and a free afternoon, it’s not difficult. Plus, you can use this exact same procedure to swap out a barrel, so I think it’s definitely worth learning.