I've been asked this question alot over the years, it's really all about the angle. New Archery Products explains it best. If you take an ethically correct quartering shot, there is no limitation to using the Spitfire broadhead. Animals that are quartering to or away at roughly a 45 degree angle will work perfectly with the Spitfire. If the quartering shot is too high of an angle (unethical archery shot), it is possible to have one blade of the broadhead open before the others, which will cause the arrow to not enter the animal correctly. This would be a shot that we would not recommend with any broadhead, mechanical or fixed blade.