Used in older shotguns, particularly black powder ones.
As metallic cartridges became more common, breech-loading shotguns began to use them too. Such ammunition could sustain high pressures without breaking and could be reloaded endlessly. Its weight and cost, however, eventually allowed paper-walled shotshell to supersede it. Furthermore, black powder eats through paper and plastic hulls as it is slow-burning, while smokeless powder does not. Modern brass shotshell is still used for super high energy loads.