AR15 Bolt Carrier Group
The AR-15 is easy to handle, simple to shoot and is so common that preppers prefer it as the weapon of choice given how easy it is to find accessories. This means that if you do own an AR-15, it pays to know how to work on it. The good news is that the AR-15 is a relatively easy weapon to inspect, maintain, and repair. If you know how to remove the bolt and charging handle from the gun in a normal field stripping process, then all you need is the following;
If you have a dedicated AR-15 multi-tool, then you are ahead of the curve as it can really help you in taking apart, cleaning, and reassembling your rifle.
The first step is removing the firing pin retaining pin which is recessed in the side of the bolt. You can use a punch and pry it out, just be careful not to use too much force. However, these pins are cheap and easy to replace. Removing this will allow you to remove the firing pin.
Next, you’ll need to remove the bolt cam pin by pushing the bolt head into the body of the carrier, then turn it 90 degrees and it should come out easily. Now, the bolt can be removed from the carrier body fairly easily, especially if you have fresh gas rings.
To disassemble the bolt, you need to remove two pins by using a pin punch and driving out the pin to remove the extractor. The extractor can be set aside for the moment as you then work on the ejector. There is considerable spring tension, but you can generally pull the ejector and the spring out the front of the bolt. Just remember to put the ejector back in the same position it was when you pulled it out.
You can pull the gas rings out if you wish or keep them in depending on their condition. You can use a dental pick to remove them if so desired. However, gas rings will generally last a long time and will not need to be removed. Also, the extractor houses the spring itself and an O-shaped ring that sits around it.
Now, you can remove the bolt carrier key which is on the carrier body. There are two cap screws that hold it in and the first is the firing pin retaining pin which allows gas into the bolt. If you can see a space between the AR-15 bolt carrier body and the key, leave it alone. If there is no space, it will need to be replaced.
Properly cleaning the AR bolt starts with the gas impingement system as that is an area of the AR-15 that can get very dirty, very quickly from the hot gases and carbon emissions. So, with the bolt out of the rifle, you should clean away all the carbon buildup as possible.
The extractor is the first place to start, particularly the groove on the underside. You will need to remove any gunk or buildup that has occurred otherwise if left unchecked it might not extract the spent round. You can use the Q-tip, screwdriver, or even a toothpick to get rid of the gunk and then replace with a light coat of oil.
When cleaning the bolt, you’ll want to start with the tail and clear out all the hardened carbon that is present. You can soak it down with Hoppes #9 or use a cleaning patch before scraping it all away with a small screwdriver. Remember to use a Q-tip to clean out the hole for the bolt cam pin as well as the locking lugs located on the head of the bolt. You will also want to apply the same cleaning philosophy to the firing pin itself as a buildup of grime will prevent its proper function. The carrier is a place where carbon will build up considerably over a short period of time, so be sure to properly clean and scrape it out with a gun scrubber or non-VOC brake cleaner.
Once the bolt has been cleaned, remember to wipe it dry so that no cleaning solvent remains. One cleaning trick is to heat the bolt to around 170F degrees after it has been cleaned and then apply a metal-penetrating lubricant before it cools. Once cooled, the bolt is ready to be put back in place.
You’ll want to put your AR-15 back together in the reverse order that you took it apart. This means putting back the ejector, extractor and spring, buffer and then the O-ring. Place the bolt inside the bolt carrier and make sure that the extractor will face the ejection port of the rifle. This is pretty important because if the bolt head is backwards or 180 degrees off, the ejector will put the fired cases back into the rifle instead of out the ejection port.
Next, insert the bolt cam pin just as you took it out, rotate the pin 90 degrees so that it will get under the gas key and then install the firing pin into the back of the bolt itself. You’ll want to check and make sure that it slides back and forth in a free manner. Once completed, install the firing pin retaining pin into the side of the bolt.
The bolt should slide back and forth as well as rotate freely once inside the carrier, although you should feel a little resistance. You can test the gas rings by extending the bolt fully from the carrier and then setting the bolt down on a flat surface. Gravity should not let the bolt carrier slide down on the bolt as it should stay extended. If it does slide down, then you will need to replace the gas rings on the body of the bolt.
Now that everything is back together, you can do some test firing of your AR-15. You’ll want to make sure that everything functions properly after you have disassembled, cleaned, and reassembled it for use.