I just realised that my Rules of Warfare don't actually say. Obviously on a roll of a 2, you missed no matter what. But does the unit actually expend ammo and generate heat? It makes no sense that it would jam before the shot, since "the vibrations of double fire" cause the jam (and if could jam before the shot was fired, then it should have a chance to jam in single fire mode).... and it's been so long since I played a sanctioned event I really don't recall. Any helpful Devs?