A volley gun is a weapon mainly used as an anti-infantry gun. They typically have several barrels mounted on a platform, which can hold multiple shots, because of this, it had a high rate of fire, which was very rare in the time, and vital. They were used sparsely from the 14th centrury to the 19th centruy.
Volley are often referred to as the past’s machine gun, however, a volley gun lacks automatic reloading and automatic fire.
The mediaval Organ Gun was designed with many small-calibre iron barrels set up on a platform, which gave it an insane rate of fire. When fired in volleys, the Organ Gun would deliver a constant shower of deadly iron.
The Organ Gun was first used by Edward III of England in 1339, during the Hundred Years War.
Age of Empires III
The Portuguese in Age of Empires III can train Organ Guns, which serves as an anti-infantry artillery weapon. Its a mobile platform with six barrels, that fires and reloads extremely fast. Just a few Organ Guns are capable of killing most of an entire army. They are quite weak against enemy cavalry though, so remember to protect them from melee.