How to Disassemble and Clean Your AR15 Bolt Carrier Group thumbnail image

How to Disassemble and Clean Your AR15 Bolt Carrier Group

5D Tactical - 1st Nov 2022

The AR-15 is historically renowned as being an incredibly reliable platform. From jungles to deserts to urban environments the AR-15 platform is known to be a reliable bang platform which is why so many militaries utilize non-civilian versions of the platform. That being said, the AR-15 is still a gun like any other that will require cleaning and maintenance to continue to run reliably and consistently. One of the most important parts of your AR-15 is the bolt carrier group (BCG). Not sure what that is? Let’s read on to see how to take care of this vital part of your AR-15!

Steps to Disassemble your Rifle

Luckily the AR-15 is an exceptionally easy weapon to maintain. Make maintenance a habit to ensure your AR-15 runs flawlessly. Excellent maintenance = excellent range days. Don’t get lazy when it comes to a weapon you trust!

Safety First

Not to kick the proverbial dead horse here but we have to say this anyway: safety first. Always make sure we keep our finger off the trigger, point the AR-15 in a safe direction, eject the magazine and clear the weapon.

Firearm safety is incredibly important whenever we do anything with a weapon so this cannot be overstated in its importance! This might seem a bit crazy but I always cycle the gun’s bolt multiple times and check multiple times to ensure the gun is clear. Worst case scenario, enjoy a little ASMR action - we all love the sound of racking an AR-15!

Things You Will Need

To clean your AR-15 Bolt Carrier Group you will not need much more than the usuals! Make sure you have the following handy:

  • Cleaning swabs
  • Gun Cleaner
  • Lubricant
  • Cotton Swabs
  • Gun Cleaning Mat or something to put underneath the BCG to keep the solvents from hurting the surface below.
  • Needle-Nose pliers ( A bullet can work as well with most rifles)


One of the best things about the AR-15 is how easy it is to break apart and clean! Field-stripping an AR-15 takes very little time - about 10-20 seconds! Just pay attention and the AR-15 will not be a difficult weapon to take down for even the newbie!

  • Make sure the bolt is forward.
  • Push out the rear takedown pin.
  • Push out the forward takedown pin (this might be unnecessary for most, I just find it easier to work on the gun overall with the upper and lower separated.)
  • Pull the bolt carrier group to the rear with the AR-15’s charging handle.

Cleaning your BCG

Disassembly of a BCG

First, locate the firing pin retainer. This can be found opposite of the bolt carrier from the forward assist serrations. Depending on what type of firing pin retainer we have, remove this with a pair of needle nose pliers or the tip of a bullet etc.

After pulling the firing pin retainer, slide out the firing pin. If it sticks due to carbon build up use your finger nail to pry it or lightly tap it on the table to get it out.

Next we’ll remove the cam pin. Look underneath the gas key and you will find the cam pin. Push the bolt inward then rotate the cam pin ninety degrees to align it parallel to the bolt carrier itself. Pull the cam pin straight out and set aside. After removing the cam pin the bolt slides out of the carrier.

Cleaning Your BCG

Cleaning your Bolt Carrier group is relatively straightforward. Make sure you have a gun cleaning mat or something else underneath before we start to spray solvents everywhere to prevent damage to anything you are working on underneath.

Coat each part of the BCG in a solvent such as CLP or something similar. If your parts have a ton of carbon build up on them then let it soak for a bit before beginning to scrub so the solvent can do most of the work!

Next start working on all the hard-to-reach places by scrubbing them down with a cotton swab dipped in solvent. You can also use cotton gun cleaning squares and a toothpick if your BCG doesn’t require much cleaning. Make sure to get into every nook and cranny, rubbing down every part and surface you can until the bolt carrier group is spic and span!

Lubricating a BCG

This one goes without saying but we need to say it anyway. Lube up every part of the BCG. Anywhere metal touches metal needs to be lubed up to ensure your AR-15 runs flawlessly. Make sure you get every hard to access part on the bolt carrier group - needle tip applicators on bottles can be great for those hard-to-reach places. Keep that AR-15 lubed up and it will run for years to come!

Common Questions

These are common questions builders will ask when learning more about bolt carrier groups:

What wears out on a BCG?

Of the parts to wear out on your BCG, watch out for the bolt, gas tube components, extractor and the firing pin. Bolt failure can be seen if you see splitting along the cam pin holes if any of your locking lugs break. Stop using your BCG immediately if you see this. Don’t forget to check your gas tube every now and then to make sure it’s getting a good seal on your BCG’s gas key. 

If rounds aren’t ejecting, you might need a new extractor. With enough rounds fired, your firing pin is bound to wear down which can cause it to fracture and break over time and use. Watch out for deformations in the firing pin - this might look like if the tip is slightly bent, blunted or chipped.

Do you oil the bolt carrier group?

You bet. We talked, above, about how it’s important to lubricate every contact point of the BCG where metal touches metal to keep everything running smoothly. Just make sure to wipe off the excess so you’re not causing a mess inside your AR-15’s internals.

When should a bolt carrier group be replaced?

If you listen to Gun Digest, they’ll tell you the rule of thumb is to change out your BCG every 5,000 rounds. Thing is, there are bolt carrier groups of varying quality and it ultimately comes down to the user’s firing schedule and degree of maintenance. Did the BCG have magnetic particle inspection, pressure test… what type of steel is it made out of? What kind of coating is on it? These are all major factors that can affect the lifespan of your BCG. 

We’d recommend you to always change it out before 10,000 rounds but the reality is that most shooters will never outshoot their bolt carrier group. If that’s not you, that’s awesome. Keep it up. Another option is to simply keep your old BCG and just change out the worn out parts within it. No need to buy a brand new engine if all you need to do is swap out a small part to get it back up and running right?

Does BCG have a firing pin?

It absolutely does, which is why it’s important to keep the BCG well maintained. Along with the firing pin, the BCG also houses the bolt, cam pin, extractor and gas key.

Build Your Next AR15 with 5D Tactical

We hope this helped out when it comes to cleaning your AR-15 Bolt carrier group. Remember that while it can seem intimidating at first, there is nothing to worry about and after a few times of stripping your AR-15 it will become so easy you can do it blindfolded!

Well, look at you disassembling rifles like a pro! Perhaps it is time to take the next step and build your perfect AR-15 Rifle or pistol? Luckily, your buddies here at 5D Tactical have you covered. Why not check out our selection of build kits or 80% lowers while you are here? Building an AR platform rifle is a lot of fun and a great way to create exactly the rifle or pistol you want - customized just to your liking! Thanks for hanging out with us here at 5D Tactical. Until next time!