The bolt is a critical part of the bolt carrier group (BCG) in modern firearms, and it works in conjunction with several other key components to ensure the reliable operation of the weapon. The bolt itself is responsible for locking into the barrel extension to seal the chamber, enabling safe and effective firing. Upon firing, the bolt rotates and unlocks, allowing it to retract and thus eject the spent cartridge case while simultaneously cocking the hammer and chambering the next round from the magazine. Key parts of the BCG include the firing pin, which strikes the primer of the cartridge to ignite the propellant; the cam pin, which fits into the bolt and allows it to rotate and lock as needed; and the extractor, which grips and removes the spent cartridge case from the chamber. Each component must function flawlessly in concert with the others, often under extreme conditions, making the quality and maintenance of these parts crucial for firearm performance and safety.