Gun mechanisms refer to the various systems and components that enable a firearm to operate. These mechanisms include the trigger, firing pin, and bolt, which work together to load, fire, and eject cartridges. When the trigger is pulled, it releases the firing pin, striking the primer of the cartridge and igniting the gunpowder, resulting in the projectile being expelled from the barrel. Different types of firearms utilize distinct mechanisms. For example, semi-automatic guns automatically reload after each shot, while revolvers require manual rotation of the cylinder. Understanding these mechanisms is essential for safe handling and operation of firearms.