Anyone shopping for a first AR-15, or thinking about building one, needs to know what the main parts are called and what they do. This short Gun Websites overview names the basic components in about two minutes.
Make it safe first
- Press the magazine release with the trigger finger and remove the magazine.
- Pull the charging handle back and look into the chamber to confirm it is empty.
- Pinch the charging handle latch and run the bolt a few times to be certain.
The lower receiver
- Under U.S. federal law, the lower receiver is the firearm. It carries the serial number, and it is the part that goes through a background check when you buy one.
- It holds the trigger group and the pistol grip, and the stock attaches to its rear.
The upper receiver
- Its job is to contain the bolt and bolt carrier and to hold the barrel.
Moving forward
- Barrel: where the cartridge is fired and the bullet is spun by the rifling.
- Handguard: surrounds the barrel so the support hand has somewhere to hold.
- Muzzle device: a flash hider, compensator or brake at the end of the barrel.
Moving back
- Receiver extension: often called the buffer tube, it holds the buffer and spring.
- Stock: rides on the receiver extension.
- Pistol grip and trigger group.
Inside
- The bolt and bolt carrier cycle each round, and the spring in the receiver extension returns them forward.
Next steps
- Explore each section in depth: AR-15 Upper Half, AR-15 Lower Half and AR-15 Accessories.
- Look up unfamiliar terms in the AR15 Glossary.
Based on a video from the Gun Websites YouTube channel. New to the AR-15? Start with Where To Start.