How Ammuntion has changed

The spark would fire the gunpowder and make it explode. Cannons were fired in much the same way. Next came the cartridge, as it is known today. The cartridge has a hollow shell made of brass. Gunpowder is packed into this, and then a lead or steel bullet is pressed in. At the closed end of the brass shell is a percussion cap ("percussion'' means "striking"). The percussion cap contains fulminate of mercury or some other substance that explodes from shock. Pulling the trigger of the gun makes the hammer strike the percussion cap. It explodes, which makes the gunpowder explode, and off flies the bullet.

Shells used in shotguns are made the same way except that many small lead balls, called shot, are packed into a cardboard case with a charge of gunpowder and a percussion cap at the end. Big cannons were soon using the same kind of ammunition as the pistol or rifle, but the "bullet" is called a shell and the explosives are contained in a shellcase. The shells used in artillery are so big that each contains a big charge of explosive that explodes when it strikes the target, causing much more damage than plain metal could.