Leonardo da Vinci’s organ gun used 33 small gun barrels arranged in three rows.
The design is usually described as a fan-shaped multi-barrel firearm. Three rows of eleven barrels could be loaded and fired in sequence or together, producing a concentrated volley. The nickname “organ gun” refers to the visual resemblance between the barrel arrangement and the pipes of a musical organ.
Leonardo’s military notebooks contain several rapid-fire and multi-barrel concepts. The organ gun aimed to increase the rate of fire by allowing one group of barrels to be prepared while another was being used or reloaded.
It should not be confused with a modern machine gun. The design still relied on separate gunpowder charges and manual loading, and there is no firm evidence that Leonardo’s specific version saw successful battlefield service.