Just a follow-up to explain my heavy bullet thinking. . . .
I feel confident that a .38 SPL 200g LSWC-K at 720fps will go straight thru anyone I may ever have to confront, and I mean all the way thru. That's regardless of how big he is, what he's wearing, or whether the shot is frontal, side, quartering, through an upraised arm, leather jacket, padded jackets, multiple hoodies & T-shirts, etc.
Granted, I live in a hot weather zone where people often dress lightly. It's a caution, however, to see how many layers we don when the temps drop below 60 degrees :-) Also, a lot of inner-city types who are my most likely threat are simply massive. I'm 51, and remember when only about one NFL player exceeded 300 lbs., but now we have many 300-pound "kids" at the high school where I teach. I'm 6' and 195 lbs, and lots of these guys dwarf me.
They also tend to be agile and fast, incredibly so in burst speed/sprints, and they are unbelievable wary. Should I ever have to shoot, I expect it to be at a fast-moving, ill-defined target who is highly accomplished at evasive maneuver, and experienced at being hurt, fighting, getting shot at, etc. Any shot I might ever have to take will be at any available angle, and probably NOT be frontal & static at a slow-footed opponent who is unready to react fast & athletically.
So, I expect shot placement will be center mass at a highly dynamic, strong, tough, athletic BG who will not likely present his vitals clearly & vulnerably to a shallow-penetrating, fast-expanding bullet. I don't want a light bullet expanding in a raised forearm, then lodging in a massive shoulder before reaching vitals.
Would I feel ill-armed with light or medium expanding bullets? Not really, because they would doubtless suffice in a high proportion of situations that could arise, although I question whether they would expand at snubbie vels thru multiple hoodies & a winter coat. I just feel that extreme penetration, wide meplat, & little/no deviation in LSWC-K bullet path give me the best chances in a worst case situation.
There are a lot of reasons I hope my theories are never put to the test. The main one is that I expect my target/BG will NOT go down when hit, unless I hit CNS by blind luck. He will either run or fight--perhaps both--depending on what he feels gives the best chance of survival. Regardless, I expect him to be physically ABLE to fight if he chooses to. That's pretty scary, but I think it's realistic. If Fackler & the FBI are correct, the main reason many fall when shot is the psychological effect. . .and the BGs I'm worried about are psychologically hardened as well as physically impressive. That makes for a tough opponent.