Personally, I was most impressed by the reports of the effectiveness of .40 S&W and .45 ACP, as detailed in a series of posts made by an alleged medical examiner who worked for law enforcement in Atlanta Georgia. His posts have been compiled here for anyone who might be interested, and if nothing else, they are interesting to read.
1. He isn't a medical examiner. He finally admits that he is an anthropologist.
2. He admits that he mainly gets "skeletal remains and the ones that are so decomposed that the ME can't do much with them". I'd like to know what kind of wound channel analysis/terminal effect studies he's doing on skeletal remains and badly decomposed bodies.
3. His numbers don't make sense. He talks about seeing huge numbers of bodies dead by gunshot--something like quarter of all the gunshot wounds in the U.S. if you actually start running the numbers on his claims.
4. He finally admits that his assessment of what calibers work best is based on "PENETRATION. Pure and simple". Which he could have said up front and saved everyone a lot of trouble. You don't have to work in a morgue to come up with a "complicated analysis" like that. Also makes one wonder how you determine penetration on skeletal and badly decomposed remains.
5. He also admits that it's often the case that the caliber used in a shooting can't be determined. I imagine that's especially true with skeletal remains. But it does raise the question of how you compare calibers if you often can't tell which calibers are even being used.
6. And, of course, there's the kicker. How is he assessing caliber failures by looking at dead people? What's the criteria for a caliber failure in a person dead by gunshot?
The bottom line is that his analysis boils down to his personal opinion based on a very simplistic assessment which he tries to bolster with claims about what he does for a living--claims that don't add up.
If you really want a fairly thorough fact check on the guy and his claims, here's a good thread to read.
By the way, at one point, a person familiar with the area that the fellow claimed to work, and the people who worked in it, mentioned trying to contact him but being ignored.
https://www.thehighroad.org/index.php?threads/maybe-the-9mm-isnt-very-effective.207527/
People who agree with the guy are happy to accept what he says at face value without digging further. Digging further reveals that the guy is trying to sell his personal opinion (and not even an especially insightful one at that) by making it sound like he has special insight which, it appears, based on his own admission, and on contradictions in his claims, he does not have.