And Vince, I am asking because I know how many people on this forum carry. To be honest I think I would get a better answer here then if I went to a gun store or even a strictly gun forum.
I like when people say 'to be honest'. It makes me feel like they are normally dishonest and this unabated honesty is a step out of their comfort zone.
I think if you think you're going to get good gun advice from this forum, and you're getting answers that include firearms that shoot a 5.7mm round for personal defense, you're getting what you deserve.
What happens when a shot you fire from your 5.7mm handgun overpenetrates and kills somebody else?
You are such a bastion of happiness and positivity Vince. Really I think that overpenetration is just as likely with a JHP .45 or 9mm as it is with the Five Seven shooting anything BUT the military/LE only armor piercing rounds. Those are a totally different subject altogether.
In my honest opinion the actual round itself matters more for (over)penetration then the caliber. Also I want to point out that having a weapon that can penetrate cover is not a bad idea at all. How many of us hike, camp, off road and the like. What happens if you have to take a shot at someone taking cover behind something like a car engine? Penetration does have a place in considering weapon and the round you will be carrying.
If the person I'm shooting at is hiding behind a car... chances are this is no longer a self-defense situation. If they're taking cover, it sounds more like they have withdrawn from the confrontation... I suppose there are some circumstances in which that would be useful though, i.e. they pull a gun, try to shoot you, miss. Followed by you taking a shot, missing, and them running for cover before firing again? Or maybe someone is trying to assassinate you and botches their shot? It might just be that I'm not very creative in handgun-defense scenarios, but I really can't think of any realistic time you (as a civilian) would need to shoot through cover unless you are the aggressor, or involved in some very shady dealings.
If you want to penetrate hard targets, but not penetrate soft targets... a round like the .357sig is reported to be a great choice. And when used with a hollowpoint, is supposedly still extremely effective at stopping people, very similar to a .357mag or .45acp in stopping power iirc.
Actually I had a very specific scenario in mind when I wrote that. I have been out shooting, packed up and started leaving, and had someone start following me. We weren't at a range, and just in the way he was driving I took it to be aggressive. This is the kind of thing that can't really be explained in text, but I just WASN'T comfortable. I had a .22 but I didn't feel like the .22 had the stopping/penetration power I wanted if I needed to shoot into his vehicle (should he brandish a weapon in my direction/start shooting) This is a situation where I want high penetration, and to be honest I also do consider this to be one of the few times I have felt like I wanted to carry a handgun.
I am sure all of the more experienced CCW holders are going to rip into me now, but hey like I said, I wasn't comfortable, and that alone is reason enough to want a weapon that will defeat a little cover.