Canister shot was a kind of anti-personnel ammunition used in cannons. It was similar to grape shot.
Canister shot consisted of a metal canister filled with lead musket bullets. When it was fired the canister would explode and the bullets would spread out causing a wide swath of destruction.
The Canister round also known as Case is still in use today. The effect is to turn a large calibre gun on an armoured fighting vehicle into a giant shotgun. This can be used against enemy infantry even when in close proximity to friendly armoured vehicles.
