AR-15 Rifle Bolt Parts & Uses

"Hi, this is Caleb Kelly again. Right now we're talking to about the bolt of the AR-15 series rifle. This is the bolt right here. It's been taken out of the charging or the bolt carrier assembly. And what you have here is a shaft where the firing pin slides through to engage the primer on the back of the bullet. Right here, you have an extractor. This grabs on to the rim of the casing of the cartridge and pulls it out after it's been fired. This right here, is where the bullet rests once it's in the chamber and the firing pin moves inside this tube, like I said, and it's going to engage. I don't know if you can see the firing pin poking out of that flush end inside of it. This is the firing pin itself. It's a little metal piece with a tip on the end and that's what strikes the primer of the bullet. This pin right here, this holds the bolt inside the bolt carrier. It also has a hole inside of it. The firing pin also moves inside this shaft right here. This last little pin right here, sits on the side of the firing pin keeping it inside the bolt carrier. And this is actually the bolt carrier right here. This is the semi-automatic version of the bolt carrier. A fully automatic version looks slightly different."