Swivel gun

A swivel gun (or simply swivel) is a small cannon mounted on a swiveling stand or fork which allows a very wide arc of movement. Another type of firearm referred to as a swivel gun was an early flintlock combination gun with two barrels that rotated along their axes to allow the shooter to switch between either the rifled or the smoothbore barrels.

Swivel guns should not be confused with pivot guns, which were far larger weapons mounted on a horizontal pivot, or screw guns, which are a mountain gun with a segmented barrel.

An older term for the type is peterero (alternative spellings include "paterero" and "pederero"). The name was taken from the Spanish name for the gun, pedrero, a combination of the word piedra (stone) and the suffix -ero (-er), because stone was the first type of ammunition fired.

It had a high rate of fire, as several chambers could be prepared in advance and quickly fired in succession and was especially effective in anti-personnel roles. It was used for centuries in Europe, Asia and Africa.