Err...That is pretty powerful. I would prefer a cooldown of something closer to 15-20 minutes for the 'particles to calm down and not be excited' which is I'm guessing how anti-matter and matter would react. But given that each shot pretty much kills its target I think that would be fair. If not that, then you could keep the few minute cooldown and make it less accurate as to give the opposing RPer a chance to react a bit more. However, that is up to you. Other than that it's fine to me.