Canister shot is a
American Civil War era antipersonnel
artillery ammunition. A tinned-iron can would be filled with small iron or lead
balls and packed with
sawdust. When fired, the artillery piece would act much like a
shotgun, spraying lethal metal balls and yellow smoke.
Like a shotgun, canister shot was most effective at short ranges -- between one hundred and four hundred yards (90-365 meters). Beyond four hundred yards (360 meters), case shot was the antipersonnel ammunition of choice for the era. At very short ranges, from a few feet (less than a meter) to no more than two hundred yards (185 meters), artillerymen would use grape shot.