How To Clean An AR-15

If you are a new owner of an AR-15 rifle and are hesitant to tackle breaking down your rifle and cleaning it yourself, don’t worry. Even if your track record for DIY projects is not stellar, this piece will walk you through the steps of performing a rudimentary cleaning of your AR-15.

Things You Will Need

Before you start the take-down process, there are a few essential items you will need to have:

  • Cleaning rag
  • Solvent
  • Gun Oil
  • Bore Brush
  • Barrel Cleaning Rod
  • Patch Adapters
  • Small Wire Cleaning Brush
  • Cleaning Patches
  • Cleaning Pick
  • Pin Punch

Before You Start

As a gun owner, your priority should always be safety. Before starting your breakdown, remove the magazine from your rifle. Then pull the charging handle back to expose the chamber. After satisfying the requirement you’re working on an unloaded gun, you can now begin the breakdown.

Separating The Upper from the Lower

If this is your first time cleaning your AR-15, it helps knowing where the pins connecting your upper receiver and lower receiver are. You will find the pivot pin just beneath the edge of the ejection port cover flap nearest the front part of the lower receiver. Push it in from the opposite side, flip the AR-15 over, and pull it out the rest of the way.

Now push out the take-down pin. You’ll find it on the lower receiver behind and directly above the lower receiver hand grip. With both pins pushed out, pull the upper and lower receivers in opposite directions to separate them.

Removing The Charging Handle and the Bolt Carrier Group

With the upper and lower receivers separated, removing the charging handle and bolt carrier group is straightforward and easy. Pull the charging handle back halfway.

You will see the bolt carrier begin to slide out as well. Remove the bolt carrier assembly and set it aside because while removing the charging handle is just as easy, you will want to know a few things that will save you time and frustration.

The charging handle will not come out entirely because it is designed not to come out during regular operation. Slowly ease it out until it stops, then lift the entire handle upward and pull it out.

Take a moment to inspect the charging handle. On each side of the shaft is a small flange. The top of the charging handle guide rail inside the upper receiver has notched openings on either side.

Installing the charging handle is as uncomplicated as easing the end into the upper receiver guide rail until the flanged part of the handle drops through the notches. It’s a simple thing but understanding how the charging handle fits into your AR-15 will save you many frustrating moments.

Disassembly and Cleaning of the Bolt Carrier Group

The bolt carrier group consists of a bolt, a carrier, and a firing pin. Hold the assembly in a vertical position and using your pin punch remove the cotter pin holding the firing pin in place.  Give the carrier assembly a couple of shakes. The firing pin should fall out independently.

Set the firing pin aside, then examine the top of the carrier assembly. You’ll see a square piece of metal beneath a short tube. That’s the bolt pin.

To remove it, turn the top and pull until it slips out. Once the pin is out you can remove the bolt from the carrier assembly. Grasp the teeth at the base of the bolt and pull it out.

Cleaning the Barrel

After hundreds of rounds, the inside of the barrel will accumulate carbon debris that needs to be brushed clean. Apply a small amount of bore cleaning solvent to your bore brush, and using your barrel rod, start at the stock end of your upper receiver and push and pull the brush through the barrel several times.

After that, remove the brush adapter and replace it with the patch adapter. Apply bore clean solvent to a patch and fit it into the patch adapter. As you did with the brush, move the patch through the entire barrel. Continue applying solvent to clean patches until the patches exit the barrel clean.

Cleaning the Bolt and the Carrier Assembly and the Firing Pin

Coat all the pieces of the bolt carrier assembly with solvent, including the firing pin. With a small wire brush, give everything a thorough scrubbing remembering to apply additional solvent when necessary.

If you find spots of carbon buildup on the firing pin, carefully remove the buildup with a pick or pocketknife. Then, use solvent to clean the firing pin again.

Once you’ve cleaned the bolt and firing pin before you reassemble the carrier group, check the gas rings on the bolt. Make sure the ring pockets are staggered and not in a row and work a few drops of lubrication into the rings with your finger.

Lubricating the Lower Receiver

There are a few essential points on the lower receiver where you will need to add lubrication, such as the hammer pivot, sear pivot, and bolt catch. A good rule of thumb for lubrication of your AR-15 lower receiver is if it moves against another piece, add a tiny drop of lubrication to it.

Putting It All Back Together

Remember to ease the charging handle into the upper receiver’s guide rail until it drops in place, then pull the handle out until it stops. The carrier group won’t fit into the upper receiver with the charging handle all the way in.

Remember that the carrier key tube of the bolt carrier fits inside the grooves of the charging handle. Also, during reassembly, make sure you extend the bolt base, so the head of the bolt retention pin is flush with the carrier assembly. If the bolt retention pin isn’t flush the head of the pin will snag on the side of the upper receiver and prevent insertion.

After everything is in place, give your charging hammer a few tugs to check for proper and functional operation. If everything is good, then it’s time to load up and head out to the range again.