How to Field Strip an AR 15 | AR 15 Disassembly

How to Field Strip an AR 15 | AR 15 Disassembly

Let’s first hope you are bored at work thinking about going out this weekend to shoot your new AR 15 and are wondering how to field strip your rifle after shooting to clean it before packing it back up. Let’s hope you are not reading this because you are having trouble with your weapon because you have been neglecting cleaning it.

There are a few things to remember to have with you when you are using your AR 15. A carry bag, the reason we like these are they unzip and make a nice workspace for field stripping after a day of shooting.

For the most part the AR 15 was designed to not necessarily need tools for simple stripping. Depending how tight your take down pins are you may need more than your thumb or finger to get them started. But typically, a key from your pocket works great for this if needed.

What to Consider First

The number one thing to remember when handling an AR 15 besides not pointing the barrel towards anything you do not want shot, is to be sure it is not loaded when working on it. Remove the magazine and clear any round that may still be chambered.

How to Field Strip an AR 15

Be sure you are in a place free of dirt or debris that may easily get blown in or onto the parts you are trying to remove for cleaning. It is also a good idea to be in a well-lit place so you can see the condition of the parts you are removing. Sure, I know some of you are planning to practice doing it blindfolded in case you ever need to, but it is important to have done it hundreds of times before doing it without looking.

What Tools are Needed to Field Strip an AR 15

As stated before, you probably do not need any tools to do a basic field strip of your AR 15, but we would suggest having a few things handy because it just makes the whole thing easier and more fun.

First, have a rag or wiping cloth, oh I know you can just use your shirt, but toss a lint free cloth in your bag before you go, you’ll thank me later. Second, you can use your keys or any other small tool for added leverage if needed, but we prefer to have a multi-tool handy. We keep one in our glove box anyway. Third, be sure your hands are clean, if they are muddy, oily, or dirty they can cause debris to be deposited in or on the parts when removed.

How to Clean a Field Stripped AR 15

After prepping your workspace with a bag or case and making sure the weapon is unloaded and has the magazine removed, you are ready to begin stripping the weapon.

Step 1: Pull Charging Handle

Pull the charging handle and ease the BCG back forward. This opens the dust cover if closed and ensures all the parts inside are not bound.

AR 15 Disassembly

Step 2: Rear Takedown Pin

Press in the rear takedown pin, flip over the rifle and use your fingertips to pull the pin the rest of the way out. Be careful that nothing springs out when the rear of the upper and lower receiver separates.

Step 3: Remove BCG

Flip the rifle upside down and slide the charging handle back. This will bring with it the BCG which you can then take hold of and remove.

Note: Be especially careful with your BCG when holding or placing down not to drop, hit, or damage the gas key located on top of the BCG. It is a precision part that can be easily damaged as well.

AR 15 Disassembly

Step 4: Remove Charging Handle

Remove the charging handle and place it down.

Step 5: Separate the Upper & Lower Receiver

You may now press in and remove the forward takedown pin to completely separate the upper receiver and the lower receiver. This makes handling the weapon easier and cleaning faster.

Note: be sure to press the take-down pins back into place as soon as you separate the upper receiver and lower receiver. The pins are apt to get easily damaged if they get knocked around, dropped, or bumped and would require replacement. This could be an abrupt way to put an end to your day or weekend of shooting.

Step 6: Inspect Lower Receiver

Inspect the inside of the lower receiver. Look for debris that may be lodged or hidden. Any debris in this area is very dangerous.

Note: Do not lubricate the trigger group. Be sure there is no oil build up inside the trigger group or lower receiver.

AR 15 Fire Control Group

Step 7: The BCG Inspection

Decide if you are going to go back to shooting right after reassembly, if so, probably just simply wiping the BCG down is enough to get you by. But if you are going to store the AR after reassembly, then you will want to disassemble the BCG.

Step 7A: Firing Pin Retaining Pin

Remove the firing pin retaining pin. Use your fingers to grab the rounded end of the pin and pull it from the BCG. Be sure to not lose it, it is a small item and easily lost.

Step 7B: Firing Pin

Remove the firing pin. The easiest way to remove the firing pin is to tap the end (the open side that faces backward) of the BCG on your work surface gently to release the pin from its location. It will often slide right out if there is not too much buildup on the pin. Simply wipe the pin down to get it clean.

Step 7C: Bolt Cam Pin

Rotate the bolt cam pin 90 degrees and pull it out. Wipe it off and place it where you can find it again.

AR 15 Bolt Carrier Disassembly

Step 7D: Bolt

Grab and pull the bolt straightforward to remove it from the carrier. Wipe it clean as well. Place with the other BCG components.

Step 7E: Gas Key Bolts

Wipe down the carrier completely with a clean cloth. The key inspection area on the carrier is the two bolts that secure the gas key to the carrier. They should be tight and properly staked. Meaning you should see small indentions or punch marks on either side of the metal surrounding the screw heads (staking or securing them into place).

Note: The gas key should be very tight against the carrier with absolutely no wobble. This would allow gas to escape and not function properly.

Step 7F: Bolt Gas Rings

Check the gas rings on the bolt. The gas rings on the bolt should form a tight seal. The way to test them is to insert the bolt back into the carrier and over a soft surface, hold onto only the bolt and see if the carrier falls off or stays in place.

Note: You should be able to wiggle the bolt side to side without the carrier coming off. If the carrier falls off, you need new gas rings. You can separately buy and replace the gas rings. Gas rings should last around 3-5k rounds with proper maintenance.

AR 15 Bolt Carrier Disassembly

Step 7G: Bolt and Extractor

Inspect the bolt and extractor. If you want to remove the extractor you can use the firing pin to remove the extractor retaining pin. It typically requires using a bit of pressure with your fingers onto the extractor to free up the pin for removal. You can then remove the extractor. If you are replacing the extractor spring, it is best practice to replace the rubber insert inside the spring at the same time. They should all come together in a kit.

It may be necessary to use a tool to remove the spring as it will probably be pressed into the extractor. *But this step is not necessary unless there is damage.

Note: The extractor spring should be replaced when replacing the gas rings.

Step 8: Final Field Strip Visual Inspection

Visually make sure everything is clean, in working order, and within arm’s reach for reassembly. If there are any damaged parts, do not put the rifle back together. It is never a good idea to reassemble a weapon with damaged parts. Be sure to tag the weapon as non-functioning if damaged as well.

After all the stripped parts have been wiped and cleaned you are ready to begin reassembly of the AR 15.

How to Reassemble a Field Stripped AR 15

Putting the whole thing back together is almost as simple as reversing the steps. With only a few additional things. There are a few places that minor lubrication is suggested. We will go over the steps and offer a few tips along the way.

(In an effort to keep the Steps for Field Stripping separate from the Things it Takes to Reassemble we will call Reassembly Things.)

AR 15 Bolt Carrier  Parts

Thing 1: Reassemble the Bolt Carrier Group

Depending on how much of the BCG you decided to disassemble, be sure to put it back together. As discussed earlier, most of the time the BCG only requires a wipe down without complete disassembly.

Note: If you completely disassemble the bolt carrier, it is usually a good idea to replace all the parts at once. Otherwise you can probably not disassemble the extractor from the bolt. Doing so without need only opens opportunity for lost or misplaced parts.

Additionally, although you may have heard that the gap in the rings on the bolt need to be out of line when reassembling, it is not the case. The rings will rotate with each cycle, so it does not matter if you rotate them or not. The weapon only needs one good ring to operate. There are three for redundancy.

Thing 1A: Re-inserting the Bolt into the Carrier

There is only one way the bolt will fit inside the Carrier. The hole in the bolt is tapered that holds the Cam Pin so insert it with the extractor in the 10 o’clock position or on the upper side with the depression.

Thing 1B: Reinsert the Cam Pin

You should be able to see that the hole is lined up for the Cam Pin in both the carrier and the bolt. Simply insert the Can Pin into the hole and rotate the pin 90 degrees so the ca you can reinsert the firing pin.

Note: the firing pin when inserted must be installed all the way flush. If it is sticking up at all the firing pin is improperly installed and will not work. When the firing pin is fully inserted, reinstall the firing pin retaining pin. For the easiest way to reinsert the firing pin retaining pin see the instructions.

Additionally, you should be able to shake the BCG after reassembly and you should be able to hear the firing pin rattle just a bit, without coming out of the BCG. If the firing pin comes out, it was not properly seated. The retaining pin should also be seated all the way in flush with the side of the carrier. You should be able to hold the carrier with the bolt forward and flick the BCG (imaging casting a fishing pole with a snap) and the bolt should click forward into the forward position without flying across the room.

AR 15 Bolt Carrier Assembly

Thing 2: Reinstalling the Charging Handle

Hold the upper receiver upside down or partially upside down. Install the charging handle so the tabs align into the slots and keep the charging handle part way out.

Thing 3: Reinstall the BCG

Then install the BCG with the bolt head forward into the upper receiver. Press the whole assembly forward until it latches. It should fit solidly into place.

Note: If you are going to apply lubricant to the BCG, now is the time. But be sure to only put a small amount of lubricant to the four spots that rub. See picture for details.

AR 15 Disassembly

Thing 4: Connecting the Two Receiver Halves

Prepare the two retaining pins in the lower receiver to the open position just before reconnection to the upper receiver. Place the lower receiver and upper receiver together so they align properly, and press the retaining pins back into place.

Thing 5: Function Check

Be sure the weapon is still unloaded (still without a magazine) and pointed away from anything you do not want shot. Pull the charging handle all the way back and release. It should be brought back to closed and secure by the buffer spring. Next flip the safety selector to safe on the lower receiver, the trigger should not move backwards and there should be no audible click sound.

Next flip the selector switch to semi. This will allow the weapon to fire. When you depress the trigger this time, pull the trigger all the way and continue to hold it all the way down. When depressed you should hear the hammer actuate. Next with the trigger still being held in the pulled position pull back the charging handle and release or ease it forward. You should then be able to slowly release the trigger and it should click again. That is the sound of the hammer coming off the disconnect and catching back on the trigger. You should then be able finish releasing the trigger and pull the trigger again. The trigger should again release the hammer and it should click again. This indicates that semi auto works correctly.

Note: if the BCG clicks when you ease it forward with the trigger pulled, it means it is malfunctioning and might fire a burst rather than fire properly.

AR 15 Assembly

Where to Get Replacement Parts

Black Rifle Depot has a large selection of replacement parts that you may need in your bag or at your home bench. With LIVE inventory and a huge selection of in-stock AR 15 parts from all the top manufacturers as well as five-star customer service Black Rifle Depot is the best place to find AR 15 parts online.

Sep 23rd 2021 Staff Writers

Recent Posts