How to Disassemble an AR-15 BCG (Bolt Carrier Group)

This article will show you how to disassemble an AR-15 BCG (Bolt Carrier Group) and Bolt in order to clean it so that it works properly every time. You will learn the instructions and steps for complete disassembly and reassembly of the BCG of an AR-15, including the extractor and ejector components.

How to Disassemble an AR-15 BCG: AR-15 Bolt Carrier Group — AR-15 Bolt Carrier Group

The BCG or Bolt Carrier Group of an AR-15 rifle (AR stands for Armalite rifle) is one of the most important parts to keep clean and lubricated. The Bolt itself does most of the work in extracting spent brass and loading a new round into the chamber. If the bolt is not properly maintained, your rifle could malfunction and fail to function when you need it most.

AR-15 Bolt Carrier Group components

The Ar-15 Bolt Carrier is made up of these components:

Bolt Carrier
Cam Pin
Firing Pin
Firing Pin Retainer

How to Disassemble an AR-15 BCG: Bolt Carrier components — Bolt Carrier components

The AR-15 Bolt itself, which fits inside the Bolt Carrier, is made of the following parts:

Bolt Body
Ejector Plunger
Ejector Pin
Ejector Spring
Extractor
Extractor Spring
Extractor Pin

How to Disassemble an AR-15 BCG: Bolt components — Bolt components

Tools you will need to disassemble an AR-15 BCG

In order to completely disassemble the BCG on an AR-15, you will need just a few tools:

A set of Gun Punches
A Real Avid Smart Bench Block (optional but super handy!)

A Gun Punch set is a basic necessity for an AR-15 Owner. Below is an example set available at Amazon.

The Real Avid Bench Block is one of several similar tools to help you remove roll pins from forearms without damage to the gun. It is possible to use a block of wood or even the edge of a workbench to support the Bolt as you tap a pin out. There needs to be room under the Bolt to allow the pin to come out.

Step-by-Step: How to Disassemble an AR-15 BCG

Fortunately, disassembling the AR-15 bolt carrier group is not difficult. You only need a few basic tools in order to do it and a little knowledge on how to do it properly. In this article I am going to show you step-by-step how to completely disassemble and reassemble the BCG for cleaning.

For this article, I will assume you already have the BCG removed from your AR-15 Rifle. If you need to know how to do this, See my Article on How to Disassemble & Clean an AR-15 Rifle.

AR-15 BCG Disassembly: Removing the Firing Pin

Locate the Firing Pin Retainer (looks like a cotter pin) and using a small tool such as a punch to pull it all the way out.

How to Disassemble an AR-15 BCG: Locate & Remove the Firing Pin Retainer with a small punch or other tool — Locate & Remove the Firing Pin Retainer with a small punch or other tool

How to Disassemble an AR-15 BCG: Pull the Firing Pin Retainer all the way out — Pull the Firing Pin Retainer all the way out

Now the Firing Pin is released and will fall out of the bolt. If it does not fall out, shake the BCG and it will come out.

How to Disassemble an AR-15 BCG: Remove the Firing Pin by letting if fall out of the Bolt Carrier — Remove the Firing Pin by letting if fall out of the Bolt Carrier

AR-15 BCG Disassembly: Removing the Bolt

With the Firing Pin now removed, we can now remove the Bolt from the Carrier. Press the Bolt all the way into the Carrier in order to position the Cam Pin for removal. Turn the Cam Pin 90 degrees and pull it out of the Bolt & Carrier. Now you can pull the Bolt out of the Carrier. This may take a bit of force.

How to Disassemble an AR-15 BCG: Press the bolt as far as it will go into the Carrier — Press the bolt as far as it will go into the Carrier

How to Disassemble an AR-15 BCG: Twist the Cam Pin As shown — Twist the Cam Pin As shown

Pull the Cam Pin all the way out of the Bolt Carrier

How to Disassemble an AR-15 BCG: Pull the Bolt out of the Carrier — Pull the Bolt out of the Carrier

AR-15 BCG Disassembly: Removing the Extractor

Now lets take a closer look at the bolt.

Here we have the Ejector and the Extractor to remove. These are both held in with a pin. We will need to push the pins out with a small punch.

AR-15 BCG Disassembly: Ejector & Extractor Pins

To remove the Extractor, hold the Bolt between the thumb and forefinger of one hand right at the Extractor Pin. Squeeze the Extractor and The Extractor Pin should come out very easily with just a push with a small punch. The Extractor and Extractor spring will then lift off of the bolt body.

AR-15 BCG Disassembly: Squeeze the Extractor as shown and push the pin out with a small punch. — Squeeze the Extractor as shown and push the pin out with a small punch.

How to Disassemble an AR-15 BCG: While squeezing the extractor, push the Extractor Pin all the way out — While squeezing the extractor, push the Extractor Pin all the way out

Remove the Extractor and Extractor Spring from the Bolt

AR-15 BCG Disassembly: Removing the Ejector

**Wear Eye Protection for the next part as springs are involved that can launch small parts at your face & eyes.

Next we will remove the Ejector from the bolt by removing the Ejector Pin. this operation is not as easy as the last one.

**Please note: Disassembling and reassembling the Ejector and Ejector Spring is only recommended if you are adept at handling small parts with springs. Please read ahead so you know what is required.

Locate the Ejector Pin on the Bolt body.

Locate the Ejector Pin on the side of the Bolt

The Ejector Pin is much tighter so it will require a 1/16″ punch and a few light taps from a mallet. To do this you will want to support the bolt with something that will not damage the bolt.

How to Disassemble an AR-15 BCG: Support the Bolt with a Real Avid Bench Block or Similar — Support the Bolt with a Real Avid Bench Block or Similar

Take the 1/16″ punch and gently tap on it until it pushes the Ejector roll Pin all the way out, and now the punch is holding the Ejector in place.

Tap the Ejector Pin out with a punch & mallet

Tap the punch all the way in. The Ejector Pin will fall out under the Bench Block

The punch is now holding the Ejector in the Bolt instead of the Ejector Pin

Remove Ejector Plunger & Ejector Spring

**Be careful on this next step. The Ejector is under spring pressure!

Place a finger on top of the Ejector on the end of the Bolt. This will prevent the Ejector from being launched across the room when you remove the punch. Then slowly remove the punch and the Ejector Plunger and Ejector Spring will come out. If they do not drop out, gently tap the Bolt on the table to get them out.

Place a finger over the end of the Bolt and slowly remove the punch.

The Ejector Plunger and spring will fall out of the Bolt.

You have now completely disassembled the AR-15 Bolt Carrier Group. Now you can clean each component using your preferred method. Then lubricate and Reassemble. If you need tips on how to clean the AR-15, See the following article:

How to Disassemble & Clean an AR-15 Rifle

Video: How to Disassemble an AR-15 BCG: Ejector & Extractor

Reassembly of the AR-15 BCG

After you clean and lubricate the components of the AR-15 BCG, it is time to put it back together. Here are the reassembly steps for the bolt Carrier Group.

First we will install the Ejector Spring and Ejector Plunger. This is arguably the most difficult part of the reassembly process, but if you are fairly good with small parts, you should be able to do it with the instructions below.

Re-installing the Ejector Spring and Plunger into the Bolt

First step is to partially insert the Ejector Pin into the Ejector Pin hole. you should be able to do this with just your fingers, but if not, place it back on the Bench Block and tap it in with the mallet. Be sure it is only in far enough to stay put. If it is in too far, the Ejector Spring and Plunger will not go in.

Push the Ejector Pin part of the way into the Ejector Pin hole.

Ejector Pin is inserted into part of the way into the hole and should look like this.

Next, drop the Ejector Spring into the Ejector hole on the end of the Bolt. Then insert the Ejector Plunger into the hole, making sure it is oriented properly. The notch in the Plunger needs to be facing the center of the bolt face or the outside edge of the bolt. I prefer it face the center, as I find it easier to line it up.

Insert the Ejector Spring into the Ejector hole.

Insert the Ejector Plunger with the notch facing the center of the bolt as shown. — Insert the Ejector Plunger with the notch up (facing the center of the bolt) as shown.

Now we need to press on the Plunger while simultaneously inserting a 1/16″ punch into the Ejector Pin hole from the OTHER side. The punch will temporarily capture the Ejector Plunger notch to hold it in place, then we will tap in the ejector Pin to replace the punch.

Capture the Plunger Notch with a 1/16″ punch

To do this, place the Bolt on the Bench Block and hold it securely in place. Take a larger punch and use it to push the Ejector Plunger into the Bolt. This will allow the 1/16″ punch to drop down far enough to capture the notch. Once it is captured we will carefully tap the Ejector pin all the way in, which will push the 1/16″ punch out the other side.

Now test the Ejector by pressing the Plunger down with a large punch, and making sure it pops back up when you release it.

Place the Bolt on the Real Avid Bench block with the partially inserted pin facing down as shown.

Place the punch in the top side of the Ejector Pin hole as shown.

Use a larger punch to press the Ejector Plunger into the bolt until the smaller punch can be pushed far enough into the hole to capture the notch

The Ejector Plunger notch is captured by the punch.

Using a larger punch or small mallet, push or tap the Ejector Pin all the way into the bolt, pushing out the small punch.

This is how it will look when the Ejector Pin is all the way in.

Test the Ejector by pressing it down and ensuring it pops back up when you release it.

Reassembling the AR-15 BCG Extractor

To reinstall the Extractor, we simply need to line it up with the holes on the Bolt and push the Extractor Pin back in. then squeeze the Extractor to the bolt and the pin should go in very easily.

Line up the Extractor on the Bolt as shown

While squeezing the extractor to the bolt, insert the extractor pin and push it all the way into the bolt

The re-installed Extractor should look like this.

Reassemble the AR-15 Bolt into the Carrier.

Now that the Bolt is reassembled, we will reassemble it to the Carrier. First step is to insert the bolt into the Carrier in the proper orientation. It will only work one way. Be sure to line it up as shown in the pictures below. After it is inserted, the big hole in the bolt must be lined up with the slot in the Carrier and the Cam Pin will then be inserted.

Line up the hole in the Bolt with the slot in the Carrier.

Rotate the Cam Pin if necessary to look like this.

Once the Cam Pin is in all the way, turn it 90 degrees as shown.

Install the Firing Pin and Retainer

Next we will install the Firing Pin and Firing Pin Retainer. Drop the Firing Pin into the center of the bolt Carrier. Push down on the head of the Pin to be sure it is seated all the way. Next, insert the Firing Pin retainer into the hole on the side of the Bolt Carrier.

Press on the head of the Firing Pin to be sure it is seated all the way.

While pressing on the Firing Pin to be sure it is all the way in, insert the firing pin retainer

How to Disassemble & Reassemble an AR-15 BCG Video

Here is a video showing most of the above steps except for the removal of the Ejector Plunger & Ejector Spring.

You are done! you have now learned how to disassemble an AR-15 BCG (Bolt Carrier Group) and then reassemble it. It really is not hard once you see how it all goes together and get your hands a little dirty doing it!

Once you do this a couple of times you will be an expert and will be able to do it quickly and easily without instruction.