ORIGINAL: sabotloader
Well we can all talk about boom/flop - but the biggest reason for the NON boom/flop, other than bullet placement, is the animals flight response. If the flight response has been alerted the animal will bolt even,though it is dead. If it is truly an ambush and the animal knows of nothing until the hit and the truma often you get boom/flop. But even then the shock must be devastating or massive breakage of motor bones. This is another reason I do say time-in-flight of the projectile is important.
Your right that is a factor also, I know from bow hunting experience, a relaxed animal that doesn't know your there is much easier to hit and will not run as far as one on alert or knows your there. I have seen that the time of ignition to time of impact is on the order of .6 seconds, that can of course give the animal time to start if's flight if it knows your around. I would say penetraton and wound channel really come into play then. Thanks for pointing this out. Chap