Cleaning an ar-15
Matt Sandy for TTAG
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Cleaning your AR-15 rifle is an oddly personal thing. Everyone seems to have their preferred way of doing it. Although there are definitely wrong ways to clean an AR, there isn’t necessarily one right way.  

In the end, if your AR ends up clean and undamaged, you’ve succeeded. Here I’m going to cover how I handle my AR-15 cleaning. The US Army was my first experience with this weapon system and is, for better or for worse, the foundation by which I do things.

Cleaning Supplies

There are tons of AR-15 rifle cleaning kits out there, but you really don’t need anything fancy to clean an AR platform rifle. An old T-shirt/rag/paper towel, cotton swab, nylon brush, bore snake and CLP was the extent of my gun cleaning kit for my first-year in. I’ve never removed any of those items from my kit, either. I’ve just added on.  

The image above is what my cleaning supplies look like now. Honestly, I use maybe 10% of what you see. I’ll discuss cleaning supplies more in-depth as I walk you through the process.

The Quick Clean

This step is a quick wipe down. This is the type of clean we do in the field, or in between live fire iterations, when things got really dirty and gritty.

Remove the rear takedown pin, then take out the bolt carrier group and charging handle.  

Cleaning an ar-15
Courtesy Author

Wipe the BCG and charging handle with a rag so they’re free of grit and black sludge.  

Cleaning an ar-15

Cleaning an ar-15

That black sludge is dirty oil. Set them aside someplace clean. Do the same with the inside of the upper receiver and lower receiver. I like using a nylon bristle brush here. Cover one end in the rag to get into the nooks and crannies.  

   Cleaning an ar-15

Cleaning an ar-15

Cleaning an ar-15

Next, run a bore snake through the barrel to make sure it’s clean. Once everything is free of dirt/grit and excessive amounts of dirty oil, re-oil it. I oil the outer three sides of the charging handle.

Cleaning an ar-15

Cleaning an ar-15

I put a drop or two of oil inside the BCG through the holes on the side.

Cleaning an ar-15

Finally, I’ll apply oil to the BCG as indicated below and spread it around with my finger.        

Cleaning an ar-15

Cleaning an ar-15

And…you’re done. This is supposed to be quick and simple. A 10-minute wipe-down to help make sure your AR runs smoothly. 

Honestly, this is how I clean my own AR 99% of the time. The internet is full of stories from guys that will go thousands of rounds without doing even this much. They just keep covering it in oil.

That will work for a while, but at a certain point your rifle will start to ooze black goo. That’s when you’ll need a more thorough cleaning, so I like to wipe away the old and put on some new.  

The Deep Clean

It’s good to do a deep clean every once in a while. Specifically, when you see a shift in performance, meaning if the accuracy starts to degrade or malfunctions start to happen. A good deep cleaning has an additional, often overlooked, benefit. It allows you to thoroughly inspect your weapon for damaged and worn parts. This can help you head off catastrophic failures.

You should use some kind of solvent that will cut through the carbon and oil for this step. Aside from military solvent tanks, I’ve used cleaning solvents like Hornady One Shot, Hoppe’s Elite Foaming Gun Cleaner, and M-Pro 7. For this article, I used Hoppes again and I tried out Hornady’s Hot Tub Sonic Cleaner. It’s not mine, but it was available and I like things that make my life easier.  

Shooter’s preference on the cleaning products…just pick something that will do the job. I also prefer to use paper towels instead of a rag here. Rags hold onto dirt. Fresh paper towels are always clean.  

Start by fully disassembling the rifle, then go piece by piece and make it clean.  

Cleaning an ar-15

Since my small parts are in the cleaner…

                  Cleaning an ar-15

Cleaning an ar-15

I’ll start with the lower. Slather on some gun cleaner. The Hoppe’s foam works, but it’s a little weak. I prefer the aerosol-based sprays. The added force of the spray seems to help blast off more grime. Either way, get it wet and wipe dry.  

Cleaning an ar-15 I focus primarily on the magazine well. I want it good and clean to make sure magazines go in and out easy.

Cleaning an ar-15

I run a cotton swab around the fire control group.  

Cleaning an ar-15

I go at it until the swabs or paper towels are coming back mostly clean. You get to choose how particular you are here. If the trigger controls are super dirty, I’ll disassemble it. Otherwise, it’s not really worth the effort.

Remove the buffer and buffer spring. Wipe all of it clean. I like to twist up some paper towels to reach down inside the buffer tube.  

Next, go to the upper receiver. The order here isn’t critical, but I start with the barrel. Ideally, I’d use a strong copper solvent like Sweet’s Bore Cleaner. When I’m doing a deep clean like this, I like to strip the bore clean. Shooter’s Choice Bore Cleaner isn’t as strong, but it’s good, and it’s what I had on hand. Follow the instructions.  

Stuff like Sweet’s will eat your barrel if you aren’t careful. Shooter’s Choice isn’t as aggressive, but I’d still follow the instructions. You’ll also need a cleaning rod, jags, and a bore brush.  

Courtesy Brownells
Courtesy Brownells
Courtesy Brownells

Use a bore-safe cleaning rod like the carbon fiber one featured or nylon coated ones. The nylon-coated ones can get embedded with grit that may scratch your barrel. Unless you are really careless with it or use it with lapping compound, it’s not really a concern. If a knuckle-dragging grunt like myself can use the nylon-coated ones in the environment that is the Army without ruining barrels, I think you’ll be OK. Just show some care. 

Wear gloves when dealing with stronger solvents. That stuff isn’t great for you. The jag holds the cloth patch that’s either soaked in solvent/oil for getting it into the barrel, or dry for removing it. The brush helps scrub out stuck-on carbon and scratch embedded copper so the solvent can work better. 

It really helps if you can put your AR in a vise (get yourself a vise block for this).  

Cleaning an ar-15

Again, just follow the instructions for whatever bore cleaner you are using. I make sure I end my bore cleaning with an oiled patch followed by one or two dry patches. This leaves a thin layer of protection for the stripped barrel.  

Next, clean the rest of the upper. I start with my nylon brush and paper towels to scrub everything I can reach.  

Cleaning an ar-15

Cleaning an ar-15

I switch to the cotton swabs for the hard-to-reach areas like around the gas tube and the star chamber. Various companies make chamber brushes, but I’ve never felt like they did much. With or without a chamber brush, I still end up digging carbon out with a cotton swab.

Cleaning an ar-15

Cleaning an ar-15 

Now for the small parts. The sonic cleaner helped, but I still have to hand-clean all the internals.  

Cleaning an ar-15

Make sure the bolt body is clean inside and out. Check inside the bolt hole for carbon buildup and scrape it out if needed. I’ll usually swab the opening to the gas key too.

Cleaning an ar-15

Cleaning an ar-15

Cleaning an ar-15

Once it’s clean, give it a good once-over for cracks or excessive wear. Also, make sure the gas key is still nice and tight.   

 Cleaning an ar-15

Next is the bolt itself. Since I forgot to remove the extractor for the sonic cleaner, I’ll take it off now and clean underneath it. Carbon likes to build up on the back of the bolt.

Cleaning an ar-15

Go ahead and scrape it off. There are some fancy tools, like this one, that can make this easier. I’ve always used dental picks or other scrapers. Obviously, be careful to not damage it.  

Once clean, inspect the gas rings for excessive wear or damage. Check the locking lugs, specifically along the back, and make sure there are no cracks. Same thing with the extractor.  

Cleaning an ar-15

If all looks good, reassemble the bolt. Check the firing pin and cam pin the same way. Once it’s fully assembled, double-check the gas rings. Do this by pulling the bolt forward and standing the BCG up on the bolt.  

The bolt body should not fall to the closed position. It should remain extended. If it falls, the gas rings need to be replaced as they aren’t providing an adequate seal.

Cleaning an ar-15

Once it’s all nice and clean, oil it back up. I oil after the deep clean the same way I do after the quick clean. I like to put a drop on the trigger springs, too. That’s an old habit taught to me during my private days. I’m honestly not sure if it’s right, wrong or meaningless, but it’s what I do.  

Once reassembled, perform a function check and…that’s about it. Again, this is how I like to do things. It works well for me. 

If you’re new to AR-15 cleaning, I encourage you to look at multiple sources. When in doubt, follow the instructions on whatever cleaning product you are using.

If you are scratching/damaging anything on the rifle, you’re doing it wrong. Stop and seek some face-to-face help from someone who has done this a few times. Preferably a gunsmith.  

 

Matt Sandy is a gunsmith who competes in both USPSA and PRC matches. 

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39 COMMENTS

  1. We used to take our weapons into the shower and soap them up really well and rinse them off thoroughly while we were in there with steamy hot water.

    We let them drain while we toweled ourselves off and get dressed.

    When we were back in uniform we would disassemble everything, shake and towel off/snake every trace of moisture. From there it was a quick task to then lube & reassemble.

    Quick and easy. We hardly got our hands and fingernails dirty.

    • We did something similar. Douse the firearm with carb cleaner. Let it work. Couple of guys in the shower with the water ripping hot. Rinse all the gunk away. Hot water dries pretty quick. Inspect and clean up anything carbon or dirt left. Shine and lube for turn in.

    • You signed for it when the Armorer issued it to you. You are responsible for any damages or loss under the UCMJ. See: ARTICLE 108 DAMAGE, WRONGFUL DISPOSITION, SALE, LOSS OR DESTRUCTION OF U.S. MILITARY PROPERTY.

      Always remember that the direction of the enemy gate is DOWN.

    • I clean & lube my AR pretty well. I have yet to disassemble the BCG fully. After perhaps 700rds no problems. Except ILLANNOY🙄

      • Depends on how it is used.

        On a range toy, it doesn’t really matter how well it is cleaned and maintained. For a fighting rifle carried and.fired in all conditions while needing to be absolutely “I don’t want to need to affix the bayonet as a last ditch” reliable then not so much.

    • Jethro the Janitor, are you working for theBiden?
      Because that’s what it would like for everyone to do with all their gunms.

  2. Use an air compressor to assist with cleaning because rags just smear grime around, etc. That said if you own firearms you should be able to at least afford an inexpensive Harbor Freight compressor, etc. And add a decent dial micrometer to the shopping list because it is a tool attention to detail DIY Gunsmiths cannot do without.
    I use a Dewey rod and pull brushes, patches through the bore in the direction the projectile travels.

    • Better off investing in a small HF sonic cleaning tank for the BCG and any other small parts. If these parts are kept meticulously clean and not over-oiled to create an effective cutting slurry inside when mixed with grit then the parts tolerances aren’t going to change much with appreciable wear.

  3. Those guys on the internet that have gone through thousands of rounds through an AR without cleaning? Bullshit. I’m not from Missouri, but I’ve hunted there a few times. So, show me.

    • On a clean range maybe if the rifle was never carried much in the field. Even with a muzzle condom, the ejector port religiously kept closed, and the magazine & well in a baggie the weapon will still eventually get full of grit and crap that mixes with any lube if dragged around in the field. Fired or not it will get dirty enough to need cleaning.

    • Seriously?
      https://bravocompanyusa.com/content/Filthy%2014%20bravo_swat_10.pdf
      https://defensereview.com/the-big-m4-myth-fouling-caused-by-the-direct-impingement-gas-system-makes-the-m4-unreliable/

      Just took a class last weekend where the instructor had one of his ARs that hadn’t been cleaned in 6K rounds. Was he a liar? I don’t know. The inside looked horrific and he was a better shot with it than I was. I do minimal cleaning with mine because I only own one and I simply don’t like dirty firearms. I took a different class last year where a guy hadn’t cleaned one ever, got to 14K rounds, he was purposefully doing an experiment and let someone borrow it and afterward saw how dirty it was and “did a favor” and cleaned it after he used it, which ticked off the owner.

      You don’t need to clean these things much or at all. Just lube, lube, lube. Failures are almost always thanks to mags, and after that, springs.

      • Obviously you never served. it’s not the gas -never said so. It’s dust, grit, talc sand. It doesn’t matter so much how many rounds have been fed through it but is a factor of time in dusty/dirty/grimy conditions. If it is only taken to a nice range I have no doubt it can be fired for thousands of rounds. Factoring in filth and just a tiny bit of shooting or too much lube and it can goop up in a day or so in the worst conditions.

        • I wasn’t addressing you, I was addressing Gadsden Flag, who mentioned nothing about sand and dirt or the military usage. It was about cleaning in the most general sense as far as I could tell because that’s all that was mentioned. I know very well about sand and dirt problems, and that you can’t get away with 30K rounds fired without cleaning in the military. Wasn’t aware you needed to serve to know such things. I am very well aware of how well made Stoner’s rifle is. But thanks for pretending to educate me.

      • “It definitely took some cleaning after that.”

        Kinda on the ‘crusty’ side after 3K? 🙂

    • AFAIC anything much less than 1000 rounds = “never fired” when it comes to a working tool such as an AR. It’s hardly even broken in and if it is your only one that you own or have used you haven’t even begun to become proficient with its operation.

      it takes 10 mags or so just to become basically familiar with it.

  4. I know a guy who would take down his AR and put it in his dishwasher. He split the upper and lower and the BCG parts went into the silverware basket.

    Wiped dry, boresnaked, oiled and then reassembled. I shook my head at the process, but it seems to work.

    This is the same guy that would occasionally put his computer keyboard in the dishwasher too. He’s a crazy bastard.

    • Makes it really hard to clean the dishwasher of the stains the water makes when mixed with powder residue.

      When we used to take weapons into the shower in the army it would make a bit of a mess of the shower walls too -hell on the grout. The M-60’s would belch a whole lot of black schmutz when washed in the hot shower water.

      I bet his wife botched if the dishwasher interior wasn’t stainless steel. That white plastic they use to line cheap dishwashers out of stains like hell too. I found this out cleaning bicycle parts in mine.

      • Best rinse it out with distilled water after the dishwasher. There are too many minerals and other dissolved solids in most tap water that will be left behind to cause issues with even the rudimentary electronics in old clicky keyboards. A final rinse in Isopropyl or even denatured alcohol is a good idea to dry everything of H²O as well.

    • I’ve heard the same story about cleaning Glocks.

      Somehow, these stories seem to mainly crop up around April 1st…

  5. Range conditions are not the same as real world field conditions.

    If it is a DI action, sell it, buy a gas piston action.
    That is the best way to keep it clean.

    And no, I do not own a AR15 as a result of using, carrying a M16A2 service rifle.

  6. I’ll admit I’m a tad OCD when it comes to clean guns and tools. Nothing chaps my arse faster than seeing a crud covered tool tossed into my toolbox, and I’m the same way with my guns. So even if I’m only firing a couple hundred rounds to test my reloads, I still come home and scrub it down and I’ll it up. My Dad insisted on taking care of your tools, whether it’s a crescent wrench or a 90 year old Win Model 1894. That’s one reason that 90 year old gun still looks as it does, with very minimal wear.
    I do appreciate hearing different techniques to keep an AR going being a relative newcomer to the platform, and no military experience.
    I’ e got an Ultrasonic cleaner, so I’ll have to give that a try next time on the BCG.

  7. Matt, thanks for an instructive article. Where i worked we shot every six weeks and cleaned the hell out of the ARs. I did not know about the gas ring test. Wii do it whenever I’m allowed to shoot my rifles again (shoulder surgery and PT says no guns beating on it)

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