Apparently the number on the side of the bow is just a number. Killing power is about the arrow, how good it flies, how good the broadheads works, and to a degree how fast it is going versus its weight and also where it is placed. No one would criticize someone using a 55 pound selfwood flat limb, but if the bow has less than that 40 on the handle, even if it shoots the same arrow faster than the selfwood, watch out. There is a point where on a standing animal the arrow will either not penetrate or bounce off with a large bone hit. i have seen a number of mechanical broadheads fail miserably out of long draw fast shooting compounds. I am not comfortable with generalities being cast over the bow weight issue, every individual needs to try to get the best set up for their own parameters. If these videos are any clue, there is plenty of power shown to kill any deer in in Iowa. I would opt for more power on something as large as a small elk for myself.