SHELL

It originated in the 15th century as a container for metal or stone shot, dispersed when the container burst after leaving the gun . Explosive shells, in use by the 16th century, were hollow cast-iron balls filled with gunpowder and lit by a fuse. Until the 18th century, such shells were used only in high-angle fire (including mortars ). In the 19th century, shells were adopted for direct-fire artillery, notably in the form of shrapnel . Modern artillery shells consist of a casing (usually steel), a propelling charge, and a bursting charge; the propelling charge is ignited by a primer at the base of the shell and the bursting charge by a fuse in the nose. In rifle , pistol , and {{link=machine gun">machine-gun ammunition, the word usually signifies the brass casing that contains the propulsive charge. In shotgun ammunition, the shell is the entire cartridge, including shot, powder, primer, and case.