In firearms such as the AR 15, the bolt rides in a part known as the bolt carrier.
basically like a normal machine gun its just smaller for better maneuverability. A submachine gun works by cycling the bolt carrier rearwards to cock the weapon. When the bolt carrier is released by depressing the trigger, it moves forward chambering a round, locking the bolt and then firing. The recoil from the round unlocks the bolt and pushes the bolt carrier rearwards again which strips the round from the chamber and ejects it from the weapon.
The bolt carrier, the firing pin, the carrier pin, the extractor, the cam pin, the bolt, the extractor retaining pin.... that's the assembly, but the charging handle is also defined as part of the bolt carrier group.
First do a full functional clear, eject the mag, rack the bolt/carrier to eject any casing. Next fully clean the gun. Check for broken or weak parts in bolt/carrier, gas system, and buffer system. Use quality ammo. If it still doesn't then take the gun to someone who knows how to work on ar15 rifles.
ejector also
Screws?There are no screws on an AR15 bolt, a pin secures the assembly
On the full auto carrier (Left) the channel on the bottom of the carrier that the sear trip lever rides in is closed on the rear end - on a semi auto bolt carrier (Right) the channel is cut all the way through.
The M16 assault rifle's bolt and bolt carrier are made of steel.
Yes, but don't use the original bolt face which came with the bolt and carrier if it's been used - get a brand new one.
Bolt Carrier Group
All machine guns follow a cycle of steps. 1. Pulling the bolt rearward(manually or electrically). It stays there until the trigger is pressed making the bolt carrier move forward. 2. Trigger activation makes the bolt carrier move forward, chambering a round and locking the bolt. 3. Firing the round by striking or electrically activating the primer. 4. Unlocking the bolt and moving the bolt carrier rearwards which unchambers the casing and ejects it out of the weapon. 5. Cycling the next round into the chamber via spring pressure from a magazine or through a cam mechanism from a belt or box.
You pull the trigger. The hammer strikes the primer. The primer ignites the powder. The ignition of the powder creates rapidly expanded gases which separate the projectile from the cartridge. These gases follow the projectile through the barrel. When these gases reach the opening, they travel up the gas tube and put pressure against the bolt carrier. The bolt carrier is pushed back. As this happens, the extractor grabs the spent casing, and it is pulled out as the bolt carrier is forced back and ejected. The bolt carrier travels to the rear of the rifle, into the extension tube. Its movement is stopped by the buffer. At that point, the return spring - which was pushed on and made tense by the travel of the bolt carrier) pushes forward, returning the bolt carrier to its original position. As the bolt carrier travels forward, it catches the rim of the next cartridge, and pushes it into the chamber. The bolt face enters the chamber behind the cartridge and rotates until it locks into the chamber as the bolt carrier is pushed forward.
Mike Bolt