How To Clean AR15 Rifles

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Basic rifle maintenance is an important aspect of owning a firearm responsibly. Cleaning a handgun or cleaning an AR-15 can seem a bit daunting for the first couple times you do it, especially if you don’t do it often enough to easily remember all the steps, but it’s a good habit to get into.

A dirty AR-15 can cause a few problems for you depending on what type of shooting you do. The residue from the gunpowder, lead, brass, and even plastic in the case of a shotgun, can gunk up the oil in the gun, cause malfunctions, and make the gun less accurate. Since you never know when you might need your AR-15 in a life-or-death situation, it’s good to keep it clean.

When To Clean, How Often, Etc.

There’s no consensus as to exactly how often you should clean each gun. It’s common for law enforcement, military, and veterans to clean their rifles and handguns after every trip to the range or other shooting excursion. While this is the best way to ensure that your gun has no malfunctions related to dirtiness, it may be hard for a lot of people to squeeze in.

how to clean an ar 15

For casual (but responsible) gun owners it can be difficult to carve out time around work and family just to get to the range to practice, let alone muddle their way through cleaning their gun after every single trip. It’s the only way to be 100% sure your gun will never malfunction due to residue build-up, but how many rounds does it actually take to cause malfunctions?

There’s no set answer to this. Every line of ammo from every manufacturer will run dirtier or cleaner than every other line of ammo. The dirtier the ammo, the faster the residue will build up. I’ve heard recommendations all the way from 500 rounds to 5000 rounds, and honestly, I don’t know which is right. I would personally lean closer to 500.

Truthfully, even if you rarely clean your gun (as long as you lubricate it), you are “probably” never going to have a malfunction due to residue build-up. You just have to decide for yourself whether “probably” is good enough. For a high-volume shooter, and especially for those who intend to rely on their firearms in life or death situations, “probably” isn’t good enough.

Cleaning Your AR-15

Alrighty, let’s hop into the actual how-to of cleaning an AR-15. The first thing you’ll need to do is disassemble it. Even before you begin the disassembly, first put down a gun cleaning mat or something else to protect the surface you’re working on. Get out the cleaning kit tools, whether you have a pre-made cleaning kit or have assembled your own cleaning kit.

Disassembly

ar 15 disassembly and cleaning

Most of the time, you’ll only need to break the gun down to three main parts: the lower receiver, upper receiver, and the bolt carrier group. We’ll talk more about it later, but for now I wouldn’t worry about going all the way down to the firing pin, buffer tube, or buffer spring. For the most part, what you can reach via the bolt carrier will have most of the carbon buildup.

Important First Step: Clear The AR-15

Before doing anything, you need to be positive that the AR-15 is unloaded and that nothing will happen when you pull the trigger. To do this, pull back the charging handle and lock it with the bolt holding lever. Then, visually inspect the chamber of the AR-15 to make sure there is not a round in there.

Then, charge the AR-15 by pulling back on the charging handle again and releasing it or by pushing the bolt catch button, point the AR-15 in a safe direction, and pull the trigger. Now you know for sure you aren’t putting anyone in harm’s way while you’re cleaning your AR.

As you clean your ar 15, it’s always good to keep the habit of pointing the barrel in a safe direction. It may seem silly when the bolt isn’t even under the charging handle, but good habits are important to keep up.

Disassembling

The first thing you’re looking for are two pins above and to either side of the trigger guard:

ar 15 cleaning

These are called take down pins. Use anything that is strong and narrow to pop those pins out. A lot of gun cleaning kits will come with a roll pin punch tool for this purpose, like the Ultimate Arms roll pin, but anything like a pen or even a bullet will work. The pins don’t need to come all the way out, in fact they shouldn’t, but once they’ve come out, the upper and lower receivers should come apart.

Next, you’ll need to get the bolt carrier group out of the upper receiver. To do this, you should be able to slide the charging handle back right along with the bolt to the rear and it should just slide right out, though you may need to jimmy it a little bit. If needed, you can also use a nylon punch or other punch pin to hit the bolt catch to get it out.

For basic cleaning, this is all the disassembling you need to do. A thorough top-to-bottom clean would involve disassembling the bolt carrier and pulling the spring out of the stock. While you can do this, most of the build-up that needs to be cleaned out is already accessible without doing all that.

Lay out all the pieces next to all your cleaning accessories.

Cleaning The Lower Receiver

This part is pretty straightforward, just use the brush that came in the cleaning kit you bought or some other steel brush to scrub, then use a white cloth to rub it down.

cleaning ar15

The main thing you’re cleaning here is the trigger assembly. Again, you can get out the buffer assembly and lube it up as you see fit, but it doesn’t really ever need cleaning.

This is one part where having a smaller wire brush can come in handy, because you’ve got some tight spaces that you need to be able to scrub down. Once you’re satisfied with the scrubbing you’ve given the area, start wiping it down with a white cloth. You don’t have to use white, but white is best because it is easy to tell when you’re no longer picking up any carbon.

The residue is a black color that is easy to see on the white, so as soon as you are no longer getting any black on the cloth, you know that area is done.

Cleaning The Upper

You can think of the upper receiver as two parts for the purposes of cleaning your AR-15: the chamber and the barrel. The steps for the chamber are essentially the same as for the lower receiver. Start with a brush and scrub around where you can fit the brush, then get a white scrap piece of cloth and start wiping all the residue off. Continue until no more black comes off.

cleaning an ar15

The barrel is a bit of a different story. Most cleaning kits will come with some kind of rod that you can use to push different cleaning implements through the barrel. There should also be a couple of attachments: a wire brush and a slotted patch tip at minimum. You can follow the same basic two-step process: brush, then cloth.

The only key tool here besides a cloth is a good bore brush. 

Attach the brush to the end of the rod, usually by screwing it on, then push the rod from the chamber through the barrel until the brush comes all the way out the end. You can unscrew the brush attachment before pulling the rod back through the barrel, or you can leave it on and pull it back through.

Run the brush end through a few times, then swap out for the slotted tip and stick a small strip of cloth in it. You’ll run this through the barrel as well, and swap out the cloth as many times as needed to get all the black residue out of the barrel.

Your kit may not use a rod like this, and even if you have one, you may prefer to use a bore snake. You also don’t have to use the cloth in the slot if your kit has a rifle mop (which I call a bore mop). Your cleaning process can vary from these instructions, as long as you’re achieving the same goal to clean an AR 15.

ar 15 cleaning

Cleaning The Bolt Carrier Group

If you want to do a more in-depth cleaning, here’s your opportunity. I’m not going to go over the disassembly of the bolt carrier group because (1) it starts to get a little complicated and (2) in my experience it isn’t as important to clean as the main pieces. This article is intended for beginners and to get the basics handled.

So essentially you’re going to take the brush and cloth combination and go after every surface you can reach on the bolt carrier group in the same way you’ve done the other components. Just scrub and wipe until the cloth comes off clean. Depending on how long your AR-15 has gone without cleaning, this could take a while.

ar-15 cleaning

Once no more residue is getting on the cloth, you’re done cleaning.

Reassembly

ar15 cleaning

We’ll talk more about lubricating down below, but if you’re not doing any lubrication right now you can go ahead and reassemble the AR. Do so by putting the bolt back in the back of the upper receiver and then reattaching the upper and lower receivers with the two pins you used to separate them.

Make sure the cam pin is in place on the bolt carrier group before you slide it in. Double check the fire control group on the ar 15 as well.

You’re not finished until you’ve done a function check to make sure the upper receiver properly attaches back into the lower receiver, that the charging handle operates as it should, and that the hammer falls when the AR-15 is charged and the trigger is pulled. Doing a test dryfire or two is a good way to check the weapon safely.

Once you’re done, lock the charging handle, clean up your bore snakes, any ammo laying around, the cleaning mat, and make sure any other tools are safely secured and your cleaning area is spic and span. Once you’ve got your AR-15 lubricated, you can get back to the range to practice shooting.

Important Tips

When To Lubricate

At some point between cleaning and shooting, you need to lubricate all of the metal-on-metal components. The trigger assembly, bolt, chamber, etc. all need to have a healthy amount of oil on them to function smoothly. Most of the time, I lube up my rifle when I’ve finished cleaning and before I’ve reassembled my rifle.

ar 15 lubrication

However, I had a soldier once tell me that I should wait until the next time I shoot and lube it right before that. I have no way of fact-checking that soldier, but it does make a certain amount of sense that the fresher the oil, the better the performance.

The properties of any oil will slowly change over time, especially when it’s exposed to the air, so if you’re cleaning your rifle but not expecting to take it out for a few months, it might make sense to hold off on lubricating until you actually take it out to the range.

Remember though, if you do this, you’re taking a risk that you need to pull out that gun at a moment’s notice in a defensive situation, it may malfunction due to a lack of lubrication. Insufficient oil is more likely to cause a malfunction than just about any amount of residue.

Different components also don’t need lubrication as often as other parts. For example, for the buffer assembly, just rubbing it down with a lightly oiled rag to give it a light coating every once in a while is going to be fine, while other parts will need more oil more often.

Depth Of Cleaning

I mentioned a few times above my thoughts on just how far you need to go in taking down the rifle to clean up all of its parts. I like to compare it to carpets. You should vacuum pretty frequently but you only need to get your carpets professionally cleaned every year or so.

When you do go through the effort of taking apart the bolt carrier group and all the other components, it’s as much about refreshing the oil as it is about cleaning off residue. Now, residue does build up in those hard-to-reach spots, it just doesn’t accumulate as fast nor is it as likely to cause a problem as the areas that are easier to reach. 

Going further allows you to reach pieces that you can’t otherwise get to, like the extractor pin, firing pin, the fire control group, and the buffer tube and buffer spring. If there is carbon buildup in those areas, gun oil will do as much for you as anything else.

There are a number of components that don’t really require cleaning, at least not with the specialized process and chemicals that we’ve been talking about. Things like the charging handle and gas tube don’t need much attention.

Gas Tube

how to clean an ar15

Don’t worry about the cleaning the gas tube. While you might get a little bit of residue out of it every few thousand rounds, for the most part the high-pressure gas filling and expelling out of the tube will keep it as clean as it needs to be. There’s no precise maintenance schedule on this, but generally you only need to replace your gas tube when you replace the barrel.

Also, in case it’s not obvious, you don’t need to scrub down the safety selector with the brush & cloth or any special tool. 

Helpful Toys Tools

There are a handful of things you can get to make life a little easier when cleaning an AR-15. One of them is Birchwood Casey Gun Scrubber. It’s a chemical that sprays into all the hard to reach places that you normally have to scrape all day at with a brush. It loosens everything so that it comes off with a cloth. It can leave a light coat if you’re not careful.

Generally, you want to pay close attention to the cleaning chemicals and cleaning solvents you use to clean an AR-15. Most ARs have at least some components that are polymer or composite instead of metal, and the chemicals or washing oil can wreak havoc on those materials. So just make sure the carbon cleaner or other chemical matches the cleaning area.

Next, you want to make sure you have the right size bore brushes, a clean rag, bore snakes, bore cleaner, and other cleaning tools. You don’t necessarily have to have the bore cleaner, but especially if you clean firearms regularly it can save you a lot of time. 

The aforementioned bore brushes come in different sizes based on what size the barrel is because you want it to be tight enough but not too tight as it slides through the barrel. I’d also recommend gloves, as the oil and carbon can be difficult to wash off your hands. Of course, you can always go all out with diamond grip microflex gloves.

Lastly, you never want to get too far into this without some trusty gun oil. Your firing pin, upper receiver, etc. aren’t going to clean themselves. 

Final Thoughts

I find it’s worth having your own kit even if you don’t intend to clean your guns as often as other gun owners. Basic gun maintenance is part of being a responsible gun owner, and since you can buy a kit for just under fifteen bucks last time I checked, most gun owners can get a basic kit with the cleaning supplies they need. 

Here’s one of a number of helpful how to videos about how to clean an ar 15. Full disclosure, I did sponsor and host this video, but it’s perfectly on topic.

With more and more gun owners opting to purchase more guns, hopefully this walk-through helps you clean your AR-15. I’ll be honest, I don’t really like cleaning my guns. It’s not awful but it’s also not particularly enjoyable for me, so I am guilty of doing the bare minimum sometimes. If you have your own method, feel free to let me know in the comments.

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