A shaft of seasoned ash as thick as a wrist, iron-headed and flighted in leather rather than feather, because no feather survives the loosing. Made to be shot from a springald or ballista and from nothing else — no arm can draw the weapon that throws it. A recovered bolt is usually worth straightening and reheading; a bolt that has gone through a shield is usually not.
Ballista Bolt
Iron-headed shaft the length of a leg; loosed by engine, not by arm.