Buying or Building Your First AR! Here is How The AR 15 Rifle Works 

In our last blog, we discussed the parts of an AR 15. Let us now take the discussion forward to the functioning of one of the most loved rifles in America – The AR 15.

Little Peek into the AR 15 History

The AR 15 was designed by Eugene Morrison Stoner in 1956 for ArmaLite to use for military operations, but because of less success of the model, ArmaLite sold this design to ‘Colt’s Manufacturing.’ In 1963, Colt manufacturing sold the fully-automatic military version of the rifle, the M-16 to the U.S. military. Because of the huge success of the full auto version, its semi-auto version, the AR 15 again came into production for law enforcement and the public. In the 1970s, Colt’s patents for the AR 15 expired, and that is when many other manufacturers started manufacturing AR 15 style rifles. Since then, different versions of the AR 15 like the semi-automatic rifle, the semi-auto carbine, or the AR15 pistol have been manufactured and famously sold in the US.

Firearm Safety

Before we get into the functioning of this amazing lightweight rifle, it is vital to go through some instructions everyone should follow for safe gun handling and to avoid any injuries or unforeseen circumstances.

• Always treat any gun as a loaded one. If you treat any gun as a loaded one, you would be highly cautious around it and mindful of how you handle it. Not toying with your gun and treating it as a loaded one would get you into the habit of safe gun handling.
• Always point the gun in a safe direction. Keeping it pointed in the safe direction will rule out damage to anyone or anything in case of an accidental discharge. This is equally important when you load or unload the gun.
• Unload the gun when done using. It is always safe to unload your gun as soon as you are done practicing and keep the firearm and ammo secured in a safe place. Check the chamber and the receiver for any unfired round and keep it free of ammo when not using it.
• Keep your finger away from the trigger until you are ready to shoot. Keeping your finger on the trigger when you are not ready to fire can have misfortunate circumstances. Do not keep your finger on the trigger till the time you are ready to shoot. This is one of the important rules of gun safety that every experienced shooter follows.
• Be sure of your target and what’s behind the target. A majority of people use a firearm to target practice on the range besides self-protection or hunting. In any case, always be sure there’s nothing behind your target as the bullet may go right through the target and hit what’s behind it. This might hurt someone or damage anything that’s behind it.
• Always keep your firearm on ‘safe’ when not using it. Although you cannot completely rely on the safety of your weapon for safe handling, keeping its safety on ‘safe’ is a step in the right direction.

Besides all the mentioned ones, there are many other safety rules you must follow while handling your weapon that could save you and others from uncertain situations. Let us now get into the details of how the AR 15 functions.

Loading the Ammunition in the Magazine

The first step to start shooting your AR is to load ammunition. Start by loading the magazine you intend to use with it. Use your dominant hand to load the rounds and your non-dominant hand to hold the magazine. When you see inside the magazine, it will have a plastic piece that stands on a spring. This is called the follower. The follower has the shape of the bullet it is supposed to hold. When you press this, it depresses the spring for the follower to go down. Start loading the rounds in the same shape as the follower. After loading every round, you need to lock it with a click using a little pressure to make sure it has fixed in its place. As you keep loading the rounds, the follower will keep going down until the magazine reaches its full capacity.

Check out our operating procedure to load and unload different types of magazines from F5 MFG.

Functioning of the AR 15

Inserting the Magazine

The first thing to start operating your AR is to insert the loaded magazine onto the gun. Before that, make sure the fire selector is in ‘safe’ position. Now, insert the magazine into the magwell, lock it with a click, and make sure its seated perfectly in the magwell.

Chambering the First Round

AR 15 fires from a closed bolt where every round is chambered as the bolt closes (locks). Loading the first round depends on whether or not the bolt is closed at the time of inserting the magazine. Now, there are two ways for this to happen.

• If the bolt was open when inserting the magazine, push the bolt catch to close the bolt and chamber the first round.
• If the bolt was already closed while loading the mag, you need to pull the charging handle to the rear and release it to chamber the first round. Pulling the charging handle would open the bolt and push it rearward. When you release the charging handle, the buffer spring inside the buttstock sends the BCG forward. The bolt takes the first round when it goes forward and locks in its place, ready to fire. The bolt also cocks the hammer and engages it with the disconnector when going rearward.

Usually, the magazine seats quite easily if the bolt is open. But if the bolt is closed, it might become a little harder to properly seat the magazine in the magwell. This is because the spring gets fully compressed if the magazine is filled to its full capacity. This is the reason some people never fill the magazine to its full capacity to leave some space for the mag to seat easily on a closed bolt.

Shooting The AR 15

Remember, the AR works on a gas impingement or direct impingement system. This means every cycle completes using the gases from the fired round.

Your gun is ready to fire only after the bullets are loaded, and the hammer is engaged to the sear by the bolt carrier’s forward movement. The action starts with pressing the trigger. The trigger cannot be pulled when the fire selector is in ‘safe’ position because the selector keeps it blocked from moving. First, move the fire selector to the ‘fire’ position, and you are ready to start shooting. Take the proper stance, rest the stock in between your chest and shoulders and press the trigger. As soon as you change the fire selector position to ‘fire,’ the recess on the selector moves to the position where you can easily pull the trigger.

How Does The AR 15 Trigger Works

Once the trigger is pulled, the hammer disengages from the sear and releases to hit the firing pin. After the shot is fired, the bolt carrier group moves rearward to release the spent casing and chamber a new round, it again cocks the hammer, and the disconnector locks it in place. Now when the trigger is released, the disconnector leaves the hammer while the hammer engages with the sear. The next pull of the trigger will again release the hammer to take the next shot.

The Main Function of the AR 15 – The Gas Impingement System

The hammer hits the firing pin. The firing pin strikes the primer at the rim of the bullet, which creates an explosion that ignites the propellant (gunpowder) inside the casing. The propellant, when ignited, reaches a temperature above 2000 degrees, creating a gas pressure inside the case. This pressure discharges the bullet from the casing through the barrel and out the muzzle at a speed of one km per second. The gases from the fired bullet leave through the gas port, enter the gas tube and leave the gas tube to enter the bolt carrier group. This enormous gas pressure moves the BCG rearward. The bolt then unlocks with the help of the cam pin and moves rearward to eject the spent casing through the ejection port cover. The buffer spring then again pushes the BCG forward. The bolt engages the hammer to the disconnector, takes a new round, and chambers it for the next shot while returning to its firing position. The bolt then locks in its place with the help of the cam pin. Then you leave the trigger, and the hammer is now engaged to the sear.

How Does the Bolt Locks And Unlocks

The cam pin is one of the parts of the Bolt Carrier Group (BCG) that does this. The cam pin moves left and right to rotate the bolt and lock it with its lugs onto the grooves on the barrel end. When the bolt moves rearward, the cam pin rotates the bolt and unlocks it to take the casing and eject it. When it comes back to its firing position, the cam pin again rotates and sets its lugs on the grooves after the bullet sits in its position.

How Does The Ejection of the Spent Casing Works

The extractor inside the BCG holds the bullet casing and preps the used casing to eject from the chamber. The spring-loaded ejector maintains the pressure on the casing. These two parts move the spent casing from the barrel extension and out the ejection port.

The Role of The Forward Assist

The residue from the fired shot leaves deposits on the inner walls of the firearm. This could create a problem for BCG to move forward and load the round because of increased friction with the upper receiver. This happens especially when you do not clean or field strip the firearm regularly. If, in any case, the BCG does not work correctly, the forward assist can help. The inner end of the forward assist works with the notches on the BCG to move it forward. The continuous push of the forward assist again locks the bolt to its position.

How Does the Bolt Stays Open After Spending All The Rounds

After all the rounds are fired, the follower on the magazine engages with the bolt catch to hold the bolt in the open position (Rearward). When you load the next magazine and push the bolt catch, the bolt will move forward, take the first round, and lock.

This is how the AR 15 works. Check out F5 MFG for AR parts made with utmost precision using the latest CNC manufacturing technology to help increase the performance of your AR. Keep an eye on our next blog that talks about the legalities of AR in different states of the US, along with the different rounds of magazines your state allows.