AR-15 style rifles are the most common rifles in the US, and one of the main reasons for this popularity and the rifle’s military adaptation and ease of maintenance. The AR platform rifles are very maintainable, and their parts are widely available. In fact, anyone with little knowledge could build an AR-15 at home using a parts kit.
If you want to do the same, or simply learn more about this incredible rifle, you need to know about all the parts that make an AR-15. So, let’s get into it.
The constriction of an AR-15 can be divided into three sections, the front, the receiver, and the buttstock. Here is an explanation of all the parts in each of these sections.
Starting from the front of the gun, the first thing you will find is the muzzle device. Different devices like Compensators, Flash hiders, and suppressors can be installed on the Muzzle on an AR. Compensators help decrease muzzle rise, flash hiders eliminate the flash of the rifle firing, and suppressors decrease the sound of the gun.
Moving back, the next thing you’ll find is the barrel of the rifle, which is mostly made from stainless steel and can vary in length, however, it has to be at least 16 inches according to the Law in the US.
The barrel is covered with the handguard, which is usually made of polymers and has Picinati rails or M-Lok to mount accessories. The handguard also houses the gas block and gas tube. The AR-15 and other similar rifles are gas-operated, which means that when a round is fired, some of the gas from the barrel is redirected to the bolt carrier group, which moves backward due to the gas pressure, ejecting the fired casing, and on its way back chambers another round. This is what makes the AR-15 semi-automatic, or in the case of the M4 or M16, automatic.
The receiver can be divided into two sections, the upper receiver and the lower receiver. The upper receiver of the AR-15 contains the bolt carrier group, charging handle, forward assist, and rear sights. The bolt carrier group is made up of several smaller parts, including the firing pin, the extractor, bolt, cam pin, and the gas key. Combined, all of these parts are responsible for loading your rifle after it is fired. The bolt moves back into the buffer tube after a bullet is fired, extracts the spent casing while moving back, and loads a new round coming forward.
The charging handle is a part of the upper receiver, which is used to manually cycle the bolt to load the rifle and the forward assist is there to improve reliability. If the bolt isn’t closing completely for some reason, the forward assist can help you close it.
The lower receiver contains the trigger group, magazine well, magazine catch and release, the safety selector, and bolt release. The trigger group consists of the hammer and the trigger, pulling the trigger releases the hammer, which hits the firing pin, and ignites the primer of the round.
The magazine well holds the magazine and the magazine catch keeps it in place. The safety selector is self-explanatory, it either blocks the trigger or allows you to shoot depending on its position. In M4s, the safety selector also has a full-auto option.
The AR-15 has a last round bolt hold open, so after a magazine is emptied, and you enter a new one, you don’t need to rack the charging handle every time, and can instead press the bolt release to allow the bolt to come forward, and have your rifle ready to fire.
The only functional part of the buttstock is the Buffer Tube. When the bolt moves backward, it has to go somewhere, so it goes into the buffer tube, which also has a recoil spring in it to absorb some of the recoils of the gun.
So, these are the parts that make up the amazing and super popular AR-15 rifle.