bullet

A bullet is a solid projectile propelled by a firearm or air gun and is normally made from metal (usually lead). A bullet (in contrast to a shell) does not contain explosives, and damages the intended target solely by imparting kinetic energy upon impact. The word "bullet" is sometimes used to refer to the combination of bullet, case, gunpowder and primer more properly known as a cartridge or round; the Oxford English Dictionary definition of a bullet is "a projectile of lead ... for firing from a rifle, revolver etc." In contrast, bullets for air guns are not part of a cartridge.