Bronze is the earliest metal tubular firearm in the world. It's a weapon. The small caliber weapon is the predecessor of the gun, and the large caliber weapon is the predecessor of the gun. Early large-caliber vessels were made of copper, so they were also called bronzes. A bronze gun made by 1332 is on display in the museum of Chinese history. It is the oldest gun in the world, with a length of 533 mm, a caliber of 105 mm and a weight of 6.94 kg. It is thick in appearance and consists of a spear mouth, a spear chamber, a medicine chamber and a tail gun. Bronzes are spherical projectiles made of stone or iron, which are used to kill enemies.