I quite agree that one needs to be very alert how things go in a shooting. And I do agree that the lower abdomen may not be as effective as the center chest hit. But I seem to recall that was advocated because many have a tendency to shoot high during shootings. BTW, it works very well with a shotgun loaded with buck, which I suspect you know.
No way would I even consider a head shot unless I was sure he's soaked up 1-2 hits center mass and appeared to not even slow down. Like you said, hard to hit and, with an angled hit, the slug may glance off, especailly with the lighter loads.
If I haven't said so, I'll agree that BG's vary alot as to how they react to being shot. And I also agree that there is little practical difference between a hit from a good HP load from either a .45 ACP or a 9mm. What really matters is how well you can shoot. E
