The ammunition used by the bronze bombards were stone balls 1 meter in diameter and weighing 400 kg. The transportation of just two bombards proved to be a logistically challenging task. They were dragged to the Fall of Constantinople by 70 oxen and 1000 men. The casting of these bombards are described by Kritoboulos 1467. He describes the clay mould and the core which was strengthened by iron, wood, earth and stone. 45 tonnes of copper and tin are said to be placed in two furnaces constructed out of large stone blocks, laid with cement and covered by fire bricks and smeared in clay. Logs of wood along with charcoal are placed inside the furnace and all the holes except the tapping channels are closed. Then bellows are put to work until the metal inside is in a fluid state. The liquid bronze is then poured into the clay mould where it is then chiseled and polished.