Dave K -
I agree. I have seen many deer hit with a 12 ga. (.72 cal.) slug and not recovered by the hunter. This was a result of poor shot placement.
Awareness of both shot placement and range is the key to success.
As I have posted on this site before, I know a guy that hunted deer for several years with a .32 cal. ml rifle. This was an old original ml that he had done considerable work on to get it in shooting order. He was not out to prove a point about taking deer with a .32, this was the only ml rifle he had at the time. He harvested several deer with that old .32, some of them being nice size bucks. As funds became available, he built himself a .45 flint and retired the .32 from deer hunting.