I would approve of bows ONLY if they aren't like the bows in Crysis or FarCry. And if people understand that it's not going to deal near the damage of a sniper or magnum pistol. They shouldn't be super strong, and if they do explosive attacks, it would have to be fairly weak, so as not to replace detonators or RL.
EDIT: Not to sound like I'm the guardian of the gate of all that enters Defiance, I just get real into these things.
Another thought, 500 would be too high, the semi auto AR only does 400, and the semi auto SR do 700. It would need to do like 300 dmg