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How To Clean and Oil an AR15: Step by Step Guide

Cleaning and oiling an AR-15 is the best way to keep your rifle running smooth and operating properly for years and years. Sure, parts degrade and need replacing eventually. But, keeping your weapon cleaned and lubricated will give you the most life out of your rifles components.

First, you’ll need the right tools and cleaners. I have an entire article dedicated to the Cleaning Gear I Use after years of trial and error I’ve now got a cleaning kit that I like.

Cleaning Gear You’ll Need:

  • Gun cleaning mat
  • Punches
  • Needle nose pliers
  • Cleaning patches/Cotton swabs
  • Bore snake/Cleaning rod
  • Cleaning solvent
  • Gun oil/Lubricant
  • Cleaning picks

You have the tools and cleaning gear ready so lets dive in. Always clear your rifle and make sure that it is safe to handle before cleaning.

How To Field Strip an AR-15

Safety first means making sure the weapon is cleared before disassembly. Remove the magazine if there is one in the rifle. I like to make sure there’s no ammo on or around the bench I’m cleaning the weapon on.

Here’s a video showing the entire process I am about to explain below. I will include clips from this video of each step along the way with written instructions.

Clearing an Ar15 Rifle

Clear the chamber by pulling back on the charging handle or side charge, however you do it, pull the BCG (bolt carrier group) back to the rear and look into the chamber to visually ensure there is no ammunition in the weapon.

Release the BCG allowing the bolt the slide forward into the chamber of the barrel.

Here’s a quick clip showing an AR-15 disassembly with written steps below:

Separating Ar15 Upper and Lower Receivers

To start, make sure the BCG is forward by pressing the bolt catch release on the side of the rifle. The BCG should already be forward if you cleared your rifle with no magazine inserted.

Pull out on the rear take down pin on the side of the lower receiver near the back. The upper will be able to swing away from the lower at this point, only attached by the front takedown pin.

Pull on the front takedown pin on the side of the receiver near the front. Those two takedown pins are the only things holding the upper and lower receiver together. The upper and lower are now disassembled.

Disassembling Ar15 Upper and Lower Receivers

Remove the BCG from the upper receiver by pulling back on the charging handle or side charge. The bolt carrier group should be able to slide right out the back of the upper receiver.

The charging handle will also be able to slide out the back of the upper receiver. You will need to push down on the charging handle while pulling back to unlatch it from the grooves it sits in the upper.

To disassemble the lower receiver, simply remove the buffer and buffer spring by pushing down on the buffer retaining detent pin and pulling the buffer and spring out of the buffer tube. You may need to push the hammer down out of the way if it isn’t already.

Here’s a quick clip showing how to disassemble an AR-15 BCG with written steps below:

Disassembling an Ar15 Bolt Carrier Group

Parts of an Ar15 BCG

  • Bolt
  • Bolt carrier
  • Firing pin
  • Firing pin retaining pin
  • Cam pin
  • Extractor
  • Extractor pin
  • Extractor spring, and O-ring

Remove Firing Pin

Start by removing the firing pin retaining pin. Its the little cotter pin looking thing on the side of the BCG that can be easily grabbed with a punch or maybe fingernail.

Once the firing pin retaining pin is out the firing pin should be able to just fall right out when you turn the BCG up vertical. If there’s lots of carbon built up you may need to bang it a bit.

Remove Cam Pin

Next, remove the cam pin that is holding the bolt into the BCG. Push the bolt all the way back into the BCG and rotate the cam pin 90 degrees and pull that sucker right out.

Remove Bolt From BCG

The firing pin is what was keeping the cam pin in place before, now you can rotate and pull it out. Now the bolt should be able to slide right out the front of the BCG.

Remove Extractor From Bolt

Remove the extractor from the bolt using a small punch to drive out the extractor pin on the side of the bolt. If you push down on the extractor, the pin should slide right out without needing to hammer the punch or anything.

The AR-15 is now field stripped as defined by the US Army. Time to clean.

I like wearing gloves while I clean firearms and it’s always advised to be in a well ventilated area.

How To Clean an AR-15 Barrel

I like to start and end with the barrel. I start with the barrel so that the cleaner has time to sit and break down the carbon build up while I clean the rest of the weapon.

To clean an AR-15 barrel use a bore snake or cleaning rod with patches to get a gun cleaner/solvent into the barrel to help break down carbon build up. The cleaner will also help break down lead and copper build up. Wipe away the cleaner and apply a small coating of lubricant.

I like to use a Quality Bore Snake (link to Amazon) like one from Hoppe’s and M-Pro 7 Gun Cleaner and Gun Oil (link to Amazon) to get the inside of the barrel nice and coated with the solvent/cleaner.

Here’s a quick clip showing how I clean the barrel to start:

Make a few passes with the bore snake coated with gun cleaner, or cleaning rod with patches, until the patches or bore snake starts coming out cleaner. I’m usually ok with a light grey color.

At this point I will leave the barrel wet with solvent, I do not run a dry patch or dry bore snake through. After I clean the rest of the weapon, I’ll come back and do another pass with cleaner.

That way the cleaner had plenty of time to break down as much junk as it could. Then I’ll pass the bore snake or cleaning rod with patches through with some gun oil on it.

If I’m going to be storing the firearm for more than 6 months, I’ll leave the oil in the barrel. Otherwise, I’ll run a dry patch through to clear most of the oil out.

You do not want to shoot the weapon with a coating of oil in the barrel.

How To Clean an AR-15 Chamber

Now that the barrel is taken care of I like to move onto the chamber. The star chamber area and barrel extension can be cleaned more easily with a Chamber Brush (link to Amazon) designed specifically for that job.

Clean the chamber and barrel extension of an AR-15 by using a chamber brush coated with gun cleaner or solvent. Cleaning picks and patches can also be used. Once clean, remove the cleaner/solvent with a dry patch and apply a light coat of gun oil.

Use Cleaning Picks

The chamber tends to be easier to get clean than the rest of the barrel. That being said, sometimes I need to get in there with Cleaning Picks to really scrape away any carbon build up that has formed. Use plastic or soft metal picks to avoid damaging your rifle.

Use A Brass Chamber Brush

Wrap a patch around a chamber brush and coat with gun cleaner. The chamber brush is designed to fit perfectly into the chamber of your barrel. That’s why you need to get the right size chamber brush, they make them for all different calibers.

Use Patches and Repeat

Move the chamber brush back and forth and around inside the chamber to break loose any build up. Swap out fresh patches with more cleaner applied until the patches start coming out clean. Light grey patches are usually clean enough for me.

Wipe Off Cleaner and Use Oil

Take a dry patch and wipe away any cleaner left in the chamber. I usually put a little coating of oil around the chamber area but not in the barrel. Wipe away any excess gun oil, you don’t want to shoot a gun with a coating of oil in the barrel.

How To Clean an AR-15 Upper Receiver

With the barrel and chamber taken care of I move onto the rest of the upper receiver. To be honest the upper receiver doesn’t usually get that dirty and can be cleaned with just some Cotton Gun Cleaning Swabs or a rag and some patches.

To clean the upper receiver of an AR-15 use cotton gun cleaning swabs with gun cleaner or solvent coating the tips. Work the cleaner around the inside of the upper receiver to remove and build up. Wipe away the cleaner and apply a light coat of gun oil.

This really doesn’t need a ton of your attention. You’ll notice a couple areas that get dirty up by the gas key and where the charging handle sits. But, the upper receiver can be wiped out and cleaned pretty easily.

Sometimes I’ll take a solvent soaked cotton swab up around where the gas tube comes into the upper when I see that area looking a little gunked up. Most everything else can be cleaned with some nylon brushes and cleaner.

I also like to wipe the outside of the upper receiver down with a rag or something. The inside of the upper where the BCG and charging handle slide around could use a drop or two of gun oil after it’s been cleaned.

How To Clean an AR-15 Bolt

The bolt is one of the more tedious components to clean but it’s where a lot of malfunctions come from. A junked up and dirty extractor has caused many headaches.

Clean an AR-15 bolt with a quality gun cleaner, a rag, cleaning picks, and some cleaning patches. Clean the bolt face and extractor areas with picks and patches to remove any build up. Apply cleaner to the entire bolt, wipe the cleaner off, then apply a light coat of gun oil.

Scrap Off Excess Build Up

I like to really spend the time scrapping the bolt face and under the lip of the extractor with cleaning picks. Those areas can get gummed up and your ammo won’t seat right, or won’t extract right. It’s where a lot problems can be prevented.

Use Plenty of Cleaner, Brushes, and Patches

Keep wiping the bolt with cleaner using new patches or a rag until the patches start coming away clean. Light grey patches is usually a good sign of being clean enough.

I like to use stiff bristle brushes like these Double Ended Nylon Cleaning Brushes from Amazon.

They make it easier than just wiping away with a rag or patches, but don’t have quite the carbon removal power as picks. They work great for moderate build up areas though.

Lubricate The Bolt

Once clean, wipe away the excess gun cleaner or solvent and apply a light coating of gun oil. Unlike the inside of the barrel, leave a nice coating of oil on there.

Clean The Ejector?

Some people like to remove the ejector and clean that area as well. There’s nothing wrong with that it’s just not a part of the official field stripping and honestly that doesn’t need to be cleaned that often.

Clean The O-Rings

The rings on the bolt can just be sprayed with cleaner and rotated a bit to let the solvent work its way in there. Just make sure you use gun oil in the same way to try getting as much solvent out as you can when you’re done cleaning it.

How To Clean an AR-15 BCG

The BCG is the bolt carrier group that contains important components like the bolt and firing pin. Keeping these parts clean keeps the firearm running smoothly.

To clean an AR-15 BCG start by disassembling and coating with a layer of gun cleaner/solvent. Use cleaning picks, brushes, rags, and cleaner to remove excess carbon build up. Wipe away remaining cleaner with a clean rag and apply a light coat of lubricating gun oil.

Clean The Firing Pin

I start by cleaning the firing pin with a rag and some cleaner. At the same time I’ll do the cam pin and firing pin retaining pin. These parts do get a bit dirty so make sure to get everything cleaned off.

Usually a quick wipe down is enough but sometimes you’ll need to scrape carbon build up off the firing pin and around the cam pin.

Clean The Bolt and Ejector

The bolt and ejector I usually clean before the rest of the BCG so those steps are listed up above.

Clean The Bolt Carrier

With bolt carrier disassembled it’s pretty easy to get in there with nylon brushes, patches, and cleaner to get all the carbon out. I will sometimes go through the area the bolt sits with a cleaning pick to really scrap any junk out of there.

The area the firing pin sits can be easily cleaned out with cotton swabs or cleaning picks. The bolt carrier in general doesn’t usually get caked with crap but it can get a bit dirty.

Lubricate The BCG

After cleaning, wipe away the cleaner/solvent with a dry rag and apply a light coat of gun oil. I’ll usually put a bit more than a light coat but you don’t need the thing sopping wet.

How To Clean an AR-15 Lower Receiver

The lower receiver may get some debris and carbon dusting in the fire control pocket here and there. But in general, the lower receiver doesn’t need to be cleaned as thoroughly as the upper receiver.

To clean an AR-15 lower receiver start by wiping any dirt or carbon from the buffer and buffer spring with a clean rag and gun cleaner. Clean the fire control group with gun cleaner and brushes. Wipe away any gun cleaner used a light coat the fire control group with gun oil.

Clean The Buffer Assembly

The buffer and buffer spring will hardly ever have a ton of build up, but it’s still a good idea to wipe away any dirt or dust that’s gotten into the buffer tube and on the spring or buffer.

There’s really no need to lubricate the buffer assembly but some people say it makes it sound a little quieter. I’ll usually put a light coat of oil and wipe most of it off. Just enough to prevent rusting.

Clean The Fire Control Group

You may see some carbon dusting showing up in the lower after a while and it’s not a bad idea to try getting some of it out. That being said, I hardly ever disassemble the fire control group to clean it.

Just getting at the trigger assembly from the top of the receiver is enough. I like to use a cotton swab with some cleaner on it to get as much junk out as I can, and then do a quick pass with some gun oil.

That’s it! Other than a quick wipe down and functions check after reassembly, the weapon is cleaned.

How Often Should an AR-15 Be Cleaned?

An AR-15 should be cleaned every 500 rounds or every 4 trips to the shooting range whichever comes first. However, if using corrosive ammunition or if the firearm has been exposed to excessive water, it should be cleaned immediately after use.

This may vary depending on the use of the weapon. For example, if the AR-15 is meant to be used for personal defense, the owner may clean after every use to ensure reliability.

On the other hand, a cheap no-name AR-15 just used for guests or as a range toy may be cleaned less often.

How Often Should I Oil My AR-15?

An AR-15 should be oiled every time it is cleaned or being stored for longer than 6 months. It’s standard practice to only oil an AR-15 after it gets cleaned. However, if a rifle is being stored for long periods of time without being used, it’s a good idea to oil it every 6 months.

After a while gun oil does dry out and there’s a potential for the weapon components to rust if left that way. A thin light coating of oil is all that’s needed to keep everything in ‘like new’ condition.

What Parts of an AR-15 Do You Lubricate/Oil?

The parts of an AR-15 that need to be lubricated and oiled are any moving components that create metal to metal contact. This includes the bolt, BCG, firing pin, and cam pin. Some users also apply a thin coat of oil to other components to reduce the risk of rusting.

Really the only necessary thing to oil and lubricate is the bolt carrier group, including the bolt. If that thing is oiled enough, it will lube the inside of the upper and the chamber for you.

However, I do apply a light coating of oil to the outside of the barrel, buffer and spring, fire control group, and generally wipe the weapon down with a clean rag to keep everything from rusting out on me.

Should You Oil Your AR-15 Barrel?

You should oil an AR-15 barrel inside and out whenever you plan on storing the weapon for longer than 6 months. However, you must clean the oil out from inside the barrel before shooting it again. Many users will apply a thin coat of oil the outside of the barrel to prevent rusting.

I always run a bore snake with some gun oil through a barrel after I clean it. But, then I run a dry bore snake through to get any excess oil out of the barrel. You don’t want to shoot a rifle with anything in the barrel, even oil.