If you’re going to own a firearm, it’s important to know how to safely take it down and maintain it. Firearms aren’t cheap, so it pays to know how to protect your investment and keep it operating in top condition.
Moreover, many of us rely on our firearms to protect our lives, making it even more imperative that they stay functional and reliable.
Luckily, in the case of the AR-15, disassembly is a pretty easy task. You don’t need to be a gunsmith or an armorer to field strip your AR for cleaning or repair. But you will need to know it’s done. Below, we’ll walk through every step.
Safety Precautions
Before you get into actually disassembling the firearm, it’s important to take the appropriate precautions, both for your own safety and to avoid damaging the firearm.
Clearing the Firearm
First, make sure the firearm is clear of all ammunition. Remove the magazine from the magazine well by pressing the mag release button on the right-hand side of the firearm, just forward of and above the trigger.
Use one hand to pull back on the charging handle and lock the bolt to the rear by pressing in on the bottom of the bolt release. That’s the ping-pong-paddle-shaped lever on the left-hand side of the firearm. If you’re having trouble doing both at once, you can also lock the bolt back by inserting an empty magazine and pulling the charging handle fully to the rear.
With the bolt locked back, visually verify that the chamber and bore are empty. For added certainty, it’s usually a good idea to stick a finger into the bore and feel for a cartridge, since it can be hard to see into the chamber in some conditions.
After clearing your firearm, release the bolt. You won’t be able to disassemble your rifle properly with it locked back
Wearing the Proper Protective Gear
If you have gloves available, particularly a disposable, non-permeable pair, now is the time to don them. If you’re going to be cleaning your AR-15 after disassembling it, it’s wise to keep the chemicals and solvents used in the process off your hands, if possible.
Even if you won’t be cleaning your firearm at this stage, a set of impermeable gloves will protect your hands from the fouling inside the firearm. The residue left by your ammo is usually very high in lead, which can be hazardous to your health if ingested.
Scrubbing your hands well with soap and cold water after working on your firearm can help reduce exposure to lead residue, but keeping it off your skin altogether is preferable.
Lastly, to protect your firearm, it’s recommended to lay down a cleaning mat or towel over your work surface before getting started.
Tools Needed
The AR-15 was designed to be as user-friendly and field-expedient as possible. The only tool strictly required for field stripping is a small, pointed object to assist in pushing out certain pins. A small Phillips screwdriver will do, or any other object of similar dimensions.
Of course, if you want to disassemble your rifle further to remove or replace parts or for a deeper cleaning, some tools may be required. Additionally, if your firearm has particularly tight tolerances, you might find it handy to have some non-marring punches to drive out stubborn pins.
Step-by-Step Guide to Disassembly
After removing the magazine and verifying that the firearm is clear of ammunition, start by pushing the rear takedown pin out. This pin is found above the grip, above and behind the safety selector.
Start on the left side and push it in as far as you are able, then move to the right side and pull it until it stops. You should hear a click when it is fully extended. If you are unable to pull the pin with your fingers, you can use a non-marring punch to drive it through, being careful not to push it further than its stopping point.
Your rifle’s upper receiver is now partially detached and will pivot freely around the front takedown pin, also known as the pivot pin for this reason. Repeat the above process with the front pin, first pushing it loose from the left side, then pulling it until it stops.
You may find the front pin harder to remove than the rear, which is normal. As with the rear pin, a punch can be used if finger strength is insufficient. With some rifles, keeping the receivers together can make it easier to remove the front pin than allowing them to separate.
With the front takedown pin removed, you can now separate your firearm into its upper and lower receiver. Set the lower receiver aside for the moment; we’ll tackle the upper receiver first.
Field Stripping an AR-15 Upper Receiver
To field strip the upper receiver, start by pulling back on the charging handle—the bolt carrier group will be retracted as well. Once a few inches of the bolt carrier group have cleared the rear of the receiver, you can use that to pull it the rest of the way out and set it aside.
Pull the charging handle back until it stops, then pull it straight down to release it from the upper receiver. Try to pull the entire thing straight down rather than levering it down from the rear. The charging handle will drop free from the receiver, and can then be set aside.
At this point, you can set your upper receiver aside as well; it should not be disassembled any further in the field. Instead, return to your bolt carrier group.
To disassemble the bolt carrier group, you’ll need to locate the firing pin retainer pin. This will be on the left-hand side of the bolt carrier group, about midway back. It looks like a small metal loop inside a recess in the side of the carrier.
When you’ve found the pin, locate its other end on the right-hand side of the carrier. Take your screwdriver, or any other pointed object, and push that pin in as far as you are able. You should see the looped end emerge on the other side.
Once it does, you can place the tip of your screwdriver inside that loop and lever the pin out from the left-hand side. It shouldn’t take much force.
With that pin removed, cup a hand over the back and underside of the bolt carrier group and tilt it back to allow the firing pin to fall free. Set the firing pin aside.
Press the bolt to its most rearward position. You’ll now need to remove the cam pin, which is visible as a rectangle on the top of the carrier. You’ll see it move as the bolt moves. It should be perpendicular to the body of the carrier. Turn it so it is parallel and no longer trapped under the gas key and pull it out.
Lastly, pull the bolt out the front of the carrier.
Congratulations, your AR-15 upper receiver is now field stripped.
Field Stripping an AR-15 Upper Receiver
Field stripping an AR-15 upper receiver is by no means difficult, but field stripping a lower receiver is even easier. The lower receiver is not typically disassembled very much for field stripping or cleaning, as the removal of most of its parts requires tools not often carried in the field.
Additionally, the removal of most of the components of the lower receiver isn’t necessary for adequate cleaning or normal maintenance.
The only part of the lower receiver you should remove in the field is the buffer and recoil spring. To remove these two connected components, press down on the buffer retainer detent. You’ll find it at the very rear of the receiver amidst the threading where the buffer tube attaches.
You can use either your screwdriver or a finger to depress the detent. Once depressed, the buffer and spring should push forward from the spring pressure and can be easily pulled free.
At this point, your lower receiver is fully field stripped.
Cleaning and Maintenance
A complete guide to AR-15 maintenance can be found here, but essentially, it breaks down to three things: removing fouling, adding lubrication, and monitoring wear.
Every five hundred rounds or so, you should break down your AR-15 according to the steps above and clean out any fouling or carbon build-up you can find. Particular areas you should pay attention to are the barrel, chamber, bolt carrier group, and trigger assembly. Remove any fouling or debris as thoroughly as possible.
After cleaning the rifle, lubrication should be applied. The exact instructions for lubrication can vary depending on your operating conditions, but in general, AR-15s should be lubricated on any point that metal is rubbing against other metal, but not in the chamber or bore.
This means you want to lubricate the bolt, firing pin, cam pin, and the rails on the bolt carrier at a minimum. Many users simply lubricate the entire bolt carrier group, except for the bolt face. It’s usually a good idea to put a light layer of oil on the recoil spring and the interface between the trigger and hammer as well.
Lastly, it’s important to monitor your AR-15 for any parts failures, particularly once your round count starts to reach the thousands. The recoil spring, firing pin, cam pin, extractor, and bolt are all common points of failure, although it may take thousands of rounds before you experience any issues.
Any part that becomes cracked should be replaced immediately. Springs should be replaced when they have lost a considerable amount of their length, or for the more cautious user, at a set interval, usually around 3,000-5,000 rounds.
Reassembly
Reassembly is as simple as following the disassembly instructions in reverse. Be careful to put the bolt carrier group together again in the right order, first inserting and bolt and securing it with the cam pin, then inserting the firing pin, then the firing pin retaining pin. It’s easy to get mixed up with all the small parts, but putting one in before its time will prevent your bolt carrier from assembling.
When reinserting the charging handle and bolt carrier group, the charging handle must be installed first, but should not be allowed to travel all the way forward and lock into the receiver. In its fully forward position, it will not allow the bolt carrier group to be installed.
If at any point you get stuck, check out our complete guide to AR-15 upper assembly. It’ll walk you through the installation of every single part of an AR-15 upper.
Conclusion
Armed with the knowledge to field strip and maintain your AR-15, you’ll be plenty prepared to keep your rifle running in peak condition for many thousands of rounds.
Eventually, though, you will need to proceed to the next level of proficiency: detail stripping. Breaking your AR-15 down into all of its individual components will help you better understand how it functions and prepare you with the skills you need to replace any part that may fail down the road.
