What Are All the Parts of an AR-15 Rifle?
Understanding the components of an AR-15 rifle is crucial for anyone looking to purchase, maintain, or simply appreciate this popular firearm. The AR-15 is a semi-automatic, gas-operated firearm that has gained immense popularity due to its modularity, accuracy, and ease of use. Let’s delve into the various parts that make up this versatile firearm.
Receiver
The receiver is the central part of the AR-15 rifle, serving as the frame that holds all the other components together. It is typically made of aluminum or steel and is available in two types: the lower receiver and the upper receiver.
| Lower Receiver | Upper Receiver |
|---|---|
| Contains the magazine well, trigger group, and fire control components. | Holds the barrel, bolt carrier group, and gas system. |
| Required for registration and ownership in some jurisdictions. | Can be easily swapped out for different calibers and barrel lengths. |
Barrel
The barrel is the tube that guides the bullet down the barrel and propels it out of the firearm. It is one of the most critical components of the AR-15, as its length and rifling pattern directly affect the rifle’s accuracy and performance.
- Length: Barrels come in various lengths, such as 16″, 18″, and 20″, with the most common being 16″ for hunting and 20″ for tactical use.
- Material: Barrels are typically made of stainless steel or aluminum, with stainless steel being more durable and corrosion-resistant.
- Rifling: The rifling pattern inside the barrel is responsible for stabilizing the bullet and ensuring accurate shooting.
Bolt Carrier Group
The bolt carrier group is a critical component that cycles the action of the firearm. It includes the bolt, carrier, gas key, and firing pin.
- Bolt: The bolt is the part that moves back and forth, extracting the spent casing, chambering a new round, and locking the bolt into the receiver.
- Carrier: The carrier is a lightweight piece that holds the bolt and moves it back and forth during the firing cycle.
- Gas Key: The gas key is a metal piece that secures the bolt carrier group to the barrel extension and allows gas to flow into the bolt carrier group for operation.
- Firing Pin: The firing pin is a small rod that strikes the primer of the cartridge, igniting the propellant and propelling the bullet out of the barrel.
Gas System
The gas system is responsible for propelling the bolt carrier group during the firing cycle. It consists of the gas key, gas block, gas tube, and gas port.
- Gas Key: As mentioned earlier, the gas key secures the bolt carrier group to the barrel extension.
- Gas Block: The gas block is a tube that connects the barrel to the gas tube and allows gas to flow into the bolt carrier group.
- Gas Tube: The gas tube is a hollow tube that carries the gas from the gas block to the bolt carrier group.
- Gas Port: The gas port is a small hole in the barrel that allows gas to flow into the gas tube.
Handguard
The handguard is the part of the firearm that covers the barrel and provides a place for the shooter to hold the rifle. It is available in various materials, such as aluminum, polymer, and carbon fiber, and can be customized with various accessories.
- Material: Handguards are typically made of aluminum, polymer, or carbon fiber, with aluminum being the most common.
- Length: Handguards come in various lengths, such as 6″, 10″, and 15″, with the most common being 10″ for tactical use.
- Customization: Handguards can be customized
