I'll second the "no CO2" comment if you want to kill wascally wabbits. From everything I'm reading about it, it just can't deliver the projectile speed that compressed air can. CO2 seems better suited for targets, where you want consistent speed more than maximum speed, or plinking, where you just want to shoot a lot. <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" />

The consensus among air rifle hunters seems to be that, to kill intermediate vermin you want around 20 footpounds of energy. Rabbits, foxes, groundhogs, all those. There's lots of rifles that can do that and more.