Musket balls are an early form of ammunition, generally made from lead. The balls are muzzle-loaded into the barrel of a long gun, or musket, wrapped in a loosely-fitting paper patch and backed with gunpowder.
This Minié ball is a conical, cylindrical soft lead bullet with three grooves around the base of the cylinder. This type of bullet, used in muzzle loading rifles, became prominent during the United States Civil War.