How To

AR-15 Hacks: Destroying 4 AR Maintenance Myths

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Here's a properly-staked AR gas key. Note how the gas key metal is bashed into the two screws so they can't turn loose. You'll hear a lot about these on gun forums.

Here's a properly-staked AR gas key. Note how the gas key metal is bashed into the two screws so they can't turn loose. You'll hear a lot about these on gun forums.

If you think people hyperventilate over hypothetical scenarios in politics, spend some time visiting online gun forums. While fun, and a great way to chit chat with others of like passion, you might leave convinced that your AR rifle has the operational complexity and maintenance requirements of the Trident II D5 ballistic missile.

Yes, your AR-15 requires care and maintenance like any other mechanical device, but don’t fret too much over it. In the past 40 years or so, the design has been improved to the point where it will function properly in some pretty nasty environments and under the worst of conditions.

With that said, here are a few things I like to keep an eye on. If you skip out on one of the detail or procedures listed below, your rifle will almost certainly not explode, but it may not function properly.

Gas rings

You’ll hear all sorts of panic about the three gas rings on your AR bolt.

I change my gas rings every nine rounds, because I shoot exceptionally tactically and need to replace them before they wear out.

If all three gas rings aren’t in place, the ‘American Idol’ voting system will crash and Clay Aiken may capture the hearts of pre-teen girls—again.

If the gaps in each ring are lined up with each other, Spain will immediately declare war with the National Rifle Association, thereby causing a massive increase in membership solicitation mailings.

Okay, so there’s a tiny bit of truth in each of these statements, but only just that—tiny.

Well, actually in the case of lined-up gaps in the gas rings, I don’t think there’s any real truth. The idea is that the gas rings are supposed to do what their name implies and seal gas. With a proper seal, the gas ported back into the bolt carrier will exert the right amount of pressure to unlock the bolt and move it and the bolt carrier back far enough, and fast enough, for proper ejection. The thinking behind the gas ring myth is that if the gaps are lined up, gas will leak between the rings and your semiautomatic rifle will function about as well as a congressional ethics committee.

These three gas rings almost have the gaps lined up! No matter.

These three gas rings almost have the gaps lined up! No matter.

In reality, the bolt and carrier move back and forth and rattle around at speeds approaching Warp 19. This action moves things, including gas rings, all over the place. No matter how carefully you line them up to avoid the dreaded alignment scandal, they’ll end up aligned on their own accord at some point.

This brings up a related point. The idea behind three gas rings in the first place is redundancy. They’re consumable items and will break on occasion. Your rifle will most likely work just fine with two, or even just one, gas ring. After all, we’re talking about a lot of gas pressure at play during recoil, so a “mostly sealed” scenario will be just fine.

Nonetheless, it’s a good idea to keep some spare rings on-hand. A pack of three costs a grand total of $2.19 from Brownells.

Muzzle devices

If you’re shooting your AR in its factory configuration, the muzzle device, whether it be a brake or flash hider of some sort, is most likely fastened tight on the fiery end of your rifle. It seems that most manufacturers use the the dreaded red Loctite on the barrel threads. If you’re not familiar with the color palette options of Loctite, blue Loctite is good for home gunssmithing use for things like mounting scope bases. It holds threaded things together, though you can still loosen parts with a wrench and a little muscle. Red Loctite, on the other hand, requires heat to loosen up. You don’t have to place the parts under the main engine of that Trident II ICBM, but you will probably need a heat gun or careful application of a blowtorch to separate parts.

Even still, it’s a great idea to check your muzzle device periodically to make sure it’s tight, especially if you’ve replaced the factory-installed one with your own device or suppressor. Recoil does silly things, and while I’m not necessarily making a confession here, it’s hypothetically possible that I may have launched both a muzzle brake and .308 silencer downrange, thankfully on different occasions.

Especially if you have replaced your factory muzzle attachment with a new brake or flash hider, keep an eye out to make sure it remains tight.

Especially if you have replaced your factory muzzle attachment with a new brake or flash hider, keep an eye out to make sure it remains tight.

Optics and mounts

I’m amazed by how easy it is for scope mounts and optics to work themselves loose. I guess it goes to show that 50,000 to 60,000 psi of pressure, when applied over and over and over again, can do strange things.

If you’re having trouble zeroing your rifle, or hitting what you’re aiming at, do a quick check on your optics mounts. You might be surprised.

If you do have to tighten things up, be sure not to over-tighten. Your scope or optic owners manual will tell you how much force to apply, but it will probably in the 15 to 20 inch-pound area. Rather than guess on how many inch-pounds you’re using, check out a gun-specific torque wrench like the Wheeler FAT Wrench. It will allow you to torque things from 10 to 65 inch-pounds.

Okay, a loose optic won’t cause your rifle to explode, but it will cause you to miss—and that’s almost as bad.

Stake your rifle’s reliability on this

If you’re new to the AR world, you might hear wise-sounding people talking about “properly-staked gas keys.” You might wonder, “what’s a staked gas key and how do I know if it’s proper?”

This whole collection of obscure terms is a bit misleading. A gas key doesn’t open anything, it’s just the part on top of the bolt carrier that mates up to the gas tube snaking its way backward from the muzzle. Gas travels from the barrel, through the gas block, into the gas tube, then into the gas key. The gas key simply directs the gas from its open end mated to the gas tube and into the bolt carrier. Think of it as a type of funnel that’s screwed tightly onto the bolt carrier.

The “screwed on” part is where staking comes into play. Remember that gas travels down the tube and into the gas key very, very quickly. As a result, the gas key screws can come loose, causing the gas key to wobble around on the bolt carrier. As these parts are intended to be solidly attached to each other, a loose gas key assembly can cause your rifle to malfunction or jam.

“Staking” simply means bashing the tar out of the gas key screw heads with a sharp object to create a dent in both the screw and gas key itself. When the metal on both is mashed together “properly,” the screws can’t come loose.

While a loose gas key won’t blow up your rifle, it will cause it to stop working. When you clean your bolt, give that gas key a solid twist to make sure it doesn’t move. If it does, it needs to be replaced.

These are just a couple of things I like to keep an eye on when I’m cleaning. Your AR rifle should be remarkably resilient. It will function reliability through some fairly adverse conditions. Keep an eye on things, but don’t get all wrapped around the axle about stuff you might hear on the gun forums. Your car will most likely still run if you wait an extra seven miles between oil changes. Your AR rifle will behave in similar fashion.

Tom McHale is the author of the Insanely Practical Guides book series that guides new and experienced shooters alike in a fun, approachable, and practical way. His books are available in print and eBook format on Amazon.

Images by Tom McHale

Any views or opinions expressed in this article are those of the author and do not reflect those of OutdoorHub. Comments on this article reflect the sole opinions of their writers.
  • Paul Buell Rider

    #5 – the Myth that you need to scrape the carbon from the inside of the carrier and the tail of the bolt. While it’s a great way to keep our troops busy, and give their DI’s something to yell about, the carbon is self limiting and will break off and fall out before it causes any functional issues. Stop wasting your time!

    • Mick

      Or buy some solvent and a CAT tool. apply, twist 5 times or so, dry, and lube … done
      Any form of carbon or copper fouling (on non hard chromed) will eventually cause corrosion.

  • Daniel Higgs

    Very nice write up, thank you for clearing these myths up. I’m guilty of being OCD about gas rings myself.

  • Jkifer

    Good write up. While serving in the Army I did see a BCG become dages due to the gas coming off of the bolt inside of the carrier due to the gaps in the rings being aligned and forced off of the bolt by gas. So it actually can result in damage. I buy the McFarland gas ring from Brownells.

  • Jim Finley

    I have to disagree about the gas rings. I served for 20 years in the Marine Corps and shot expert every time but one; one year on record day, though, I almost lost my expert badge because of this. I’d been shooting well all week and was having a great day, but when I started my 500-yard slow fire I knew after two rounds something was wrong. I had a vertical string of over two feet, with horizontal spread limited to the usual 6 inches or so. I managed to keep them in the black, but if If I’d been shooting on the targets used at the 200 and 300 yard line, that much variation would have had me in the 3 ring at 12 and 6 o’clock. As soon as I got done that day I broke the rifle down and the rings were lined up. I realize that’s a small sample size to draw conclusions from, but it was the only time I’d seen them lined up, and the only time I’d ever had my accuracy suddenly disintegrate in the vertical that way. With my own ARs, I replace the stock rings with McFarland one-piece rings.
    Semper Fi,
    Captain J.R. Finley, USMC, retired

  • HBumgarner

    Need to add my 2 cents worth on the gas rings. I have seen problems with extraction when the rings are lined up. Not enough gas was trapped to cycle the bolt carrier group properly causing failure to extract and to cock. I have also never seen a ring break although I take it others have. 35 years of shooting the M16A1/A2 / AR platform, almost all breakages were of parts put in by someone other than the factory. I have fired thousands of live rounds and likely another thousand of blanks and have never had a malfunction that I can’t blame on Operator Error.

    H.D. Bumgarner
    Capt USMCR (Ret).

  • Doug

    I actually laughed out loud when I read the bit about launching your suppressor and muzzle brake downrange. Not much does that nowadays, but that one tickled me.