eli5: Why do machine guns or gatling guns have to spin to shoot?

Question

Just playing Call of Duty and noticed the death machine spins and I always wondered why.

In: Engineering

Answer 1

In the case of the gatling gun it has 5 barrels and one bullet is loaded and fired into each barrel then the spent casing is ejected and a new cartridge is inserted into the barrel and fired. This happnes with each barrell as it rotates and fires