Before the advent of the common cannon this massive weapon was used to siege Castles and as Artillery. It was inaccurate and most times if not primed properly it used to explode in the face of its firing crew.

Bombards were indeed large, inaccurate early cannon used in medieval siege warfare before more advanced artillery was developed. They were dangerous to operate and could explode if not properly handled. Trebuchets and catapults were mechanical siege engines (not gunpowder weapons), while petards were small explosive devices used to breach gates or walls - not large artillery pieces.