Yesterday, I talked about buying your first AR, so today, I thought I’d do a quick post on how to do an AR disassembly. I’ve always called it a field strip. In other words, how to pull the gun far enough apart to clean and check it for function.
As always, make sure the weapon is unloaded with no ammo in the room (double, triple, and quadruple check). You can never be too sure the gun is unloaded. Check again.
Once you have checked to make sure it’s unloaded, make sure you let the bolt go home. If you leave it locked back, you will be sorry.
Start by removing the rear take down pin. Do this by pushing the pin from the left to the right. The pin is designed to be retained so you don’t lose it, so don’t beat on it to get it out.
Once the pin is out, the upper receiver will rotate down. This is commonly called breaking it down shotgun style. In the field, I will not remove the front take down pin. But at home I like to break the AR into two different pieces, the upper receiver and lower receiver.
Then pull the bolt carrier group out.
Once the bolt is out, take the charging handle out by pulling it three quarters of the way out and push it down into the receiver.
Now the upper and lower receiver are as far as you should go unless you have a manual or know what you are doing. Removing the pins that hold the trigger in or unscrewing things can make things pop out. Most of this stuff (especially in the lower) are under spring tension or holding springs in.
The bolt carrier group is called a group for a reason. There a bunch of pieces in there. Start by taking out the firing pin retaining pin (yes it is one of the most confusing names ever). I like to use a knife or punch I’ve broken too many fingernails trying to get that pin out.
Once the firing pin retaining pin is out, the firing pin will fall out. Once the firing pin is out, push the bolt face in and out. You’ll see the cam pin move under the carrier key.
Turn the cam pin 90 degrees. Then pull the cam pin out. Once the cam pin is out, the bolt will pull out the front of the bolt carrier. The Marine Corps says that is as far down as you should go. I think you should remove the extractor to check the spring when you break the rifle down. In my experience, this has been the number one spring that causes the rifle to malfunction. It gets broken, wears out, or gets lost easily.
To remove the extractor, use the firing pin or punch to push the extractor pin out. The extractor is under spring tension so you might have to push on it a little to get the pin out. Don’t force it or you could break the spring.
Once the extractor pin is out, the extractor will come off. The spring is on the inside and should be stuck to the extractor by a little insert. Just look at it, don’t take it off, it’s hard to get back on there correctly.
Last, don’t forget the buffer and buffer spring. Simply push down on the detent behind where the rear takedown pin goes in the lower receiver and out will pop the buffer and spring.
That’s it. Anything else requires tools and a lot of knowledge and patience.