I've shot several deer each with a 9, 40 and 45 acp. I noticed a significantly quicker kills and penetration on deer with the 45 than the 9 and 40. I have read lots of articles saying that for law enforcement the 9 is just as good at stopping a threat. FBI has even gone back to the 9mm but I just don't buy it. But other than a handful of deer with each I really don't have much to disprove that theory. who buys into the 9 being as good or better for duty carry or hunting for that matter.
