AR-15 Maintenance and Cleaning: Everything You Need to Know

Last Updated on November 11, 2023.
AR-15 Maintenance and Cleaning Everything You Need to Know

Every gun needs to be cleaned and lubricated from time to time to ensure it performs at optimum efficiency. The AR-15 is no exception. Fortunately, field-stripping the AR-15 is simple. And so is the cleaning and lubrication process.

Gun Cleaning

The AR-15 developed a reputation early on as being more prone to fouling due to its unique operating system in which gas is fed directly into the bolt carrier group. However, when properly maintained, the AR-15 is a highly reliable rifle platform that should continue to function for many years and thousands of rounds.

AR-15 Field Stripping and Maintenance

If you’re wondering how to clean an AR-15, the process is relatively simple, but before beginning disassembly and maintenance, it’s important to clear your rifle

Clearing a gun is when you determine that its chamber is unloaded so that it’s safe to handle. While keeping the muzzle pointed in a safe direction, retract the charging handle until the bolt carrier group is in its rearmost position inside the upper receiver. 

Lock the bolt open by lifting the bottom lobe of the bolt catch with your non-dominant hand. 

Perform a visual and tactile inspection of the chamber to ensure that it is unloaded. A tactile inspection consists of inserting your little finger into the chamber through the open ejection port. 

Once you have determined that the chamber is empty, you may depress the bolt catch to close the action. You can now drop the hammer by pressing the trigger. 

Field Stripping

Field stripping is the level of disassembly necessary to facilitate routine maintenance, such as cleaning and lubrication, and usually involves breaking the gun down into its major component groups. To field-strip an AR-15, you can use a pointed object, such as a punch or the tip of a cartridge, to press the rear takedown pin in and pull it out from the opposite side. This pin is located at the rear of the lower receiver, above and behind the selector lever. 

Pulling this takedown pin out allows you to pivot the lower receiver down on the front takedown/pivot pin. Pulling the front takedown pin out will allow you to separate the upper and lower receivers. 

If you want to remove the buffer and action spring, you can use the same punch or tool to depress the buffer retainer and slide the buffer spring assembly forward and out of the receiver extension. 

Whether this is necessary will depend on the extent of the maintenance that you intend to perform. This can also be useful for inspecting the action spring’s compression length.

Retract the charging handle and remove the bolt carrier group from the upper receiver. 

Using a pointed tool, such as an Allen keyremove the firing pin retaining pin and the firing pin from the bolt. This frees the cam pin, which you can rotate and lift out of its track in the bolt carrier. 

Once you’ve removed the cam pin, you can remove the bolt from the bolt carrier. You may also consider removing the extractor by pressing the extractor pin out. Further disassembly is probably not necessary for the purposes of cleaning and lubrication. 

Cleaning — First Steps

The process of how to clean an AR-15 is simple. If you want to do it fast, you can place the bolt and parts like the firing pin, cam pin, and extractor (if you’ve removed it from the bolt) into a metal bowl or dish containing cleaning solvent. 

You should keep the cleaning solvent that you’re using, such as Hoppe’s No. 9, away from heat sources at all times, and refrain from smoking near volatile chemicals. It’s also important that you clean your rifle in a well-ventilated area. 

Inspect the action spring and buffer. With a shop rag or lint-free cleaning cloth, lightly oiled, wipe the action spring and buffer, and re-insert the assembly into the receiver extension/buffer tube. 

For cleaning the barrel, always clean from the breech to the muzzle. There are specialty chamber brushes you can buy that also clean the barrel extension locking lugs. Dip a phosphor-bronze chamber brush in solvent and scrub the chamber. 

Use a cleaning rod with a .22-caliber phosphor-bronze bore brush to clean the barrel. (If your AR-15 is not chambered in .223 Remington/5.56mm NATO, use a bore brush that corresponds to the caliber of your rifle — e.g., .30 caliber for .300 Blackout.) 

This bore brush, too, should be soaked in solvent. Inserting the brush from the breech to the muzzle, remove the brush from the muzzle end before withdrawing the rod through the barrel. This will avoid depositing any contaminants or fouling that the brush collected on the first pass through. 

Attach a jag, slotted tip, or other head to the cleaning rod and run a cleaning patch through the bore, removing the patch from the muzzle. Follow this with as many patches as necessary to clean the barrel. Continue to run cleaning patches through the barrel until they exit the muzzle white. 

Cleaning the Bolt

If you’ve left the bolt soak in solvent during the barrel cleaning process, the cleaning process will be even simpler. 

You can use a wire brush to scrub the outside of the bolt, removing any fouling adhered to the locking lugs or bolt body. Pay attention to the tail and gas rings — these need scrubbing too. Whether you should stagger the gas rings or not is a matter of debate, but you should check their condition

If you own an AR-15 rifle that uses the Stoner gas system, often used interchangeably with “direct impingement,” you should also clean out the gas key. You can do this with a pipe cleaner, cotton swab, or another narrow tool.

You may also want to use a utility brush or wire brush to clean the inside diameter of the bolt carrier, depending on how dirty it is. 

Lubricating the AR-15

How much you should lubricate the AR-15 is the subject of debate, but the gun doesn’t need to drip oil. Lightly oil those parts that reciprocate or are under stress during the cycle of operation. The cam pin, firing pin, and gas rings in the bolt should receive a few drops. You should also lightly oil the fire control group, including the hammer pivot spring and the selector lever and bolt catch. 

Lightly oil the dust cover and forward assist and wipe the exterior clean.

​Manuals and Cleaning Kits

Always consult the owner’s manual of your firearm before disassembling and cleaning it. The instructions regarding proper cleaning and lubrication may differ depending on your rifle’s particular make and model. 

Assembling or buying a cleaning kit is an essential part of gun care. You have the necessary tools, such as cleaning rod and attachments, bore and chamber brushes, solvents, and oils, to keep your AR-15 rifle operating at peak performance.

A Well-Maintained AR-15 is More Reliable

Maintain your AR-15 by cleaning and lubricating it at regular intervals or after prolonged shooting sessions. You’ll preserve its inherent accuracy longer and keep it firing for years.

If you're looking for a buying guide for AR-15 pistols, visit this page.

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