My H&K P30 has a double stack 15 rnd magazine. If I put that much lead out and still haven't stopped the bad guy something is seriously wrong. I do think the .45 with double the lead has a pretty good chance of stopping a bad guy. The Kimber I have is easier to carry concealed. If it was strictly to carry concealed I think the Ruger LC9 my wife has is a great choice. The .40 seems like a good compromise. I set out to keep things simple with 1 caliber but somehow it has mushroomed into much more than that. I know I have a lot to learn about this gun stuff but damn, just owning one makes me happy.