Put a wooden arrow through a vampires heart. Just as good as a stake if you ask me. You don't really have that option with a gun, same goes for werewolves. Just swap the arrow head for a silver version. With a gun the bullet has to be low calibur or you run the risk of the silver being dispersed before impact. Conceivably the only thing I could see a bow being less effective on than a gun as far as the super natural are concerned is maybe a ghoul or a spirit and in the later case gun wins cause you can load rock salt into a shotgun shell. so by the look of it Bow 2 Gun 1. So im with Eddie I don't see an issue