I am retired from Pathology. I have examined bullets from most of the calibers. Some from living and some from the dead, including .22LR. The body had defense mechanisms for survival like the skin being elastic and have the ability to close off wounds for example. It can be difficult to tell what caliber the person was shot with because of these bodily defense mechanisms. The 1/10 of an inch in diameter is not enough of a difference to matter in a practical sense since the body can adapt etc. It still is bullet placement and won't make up for lousy shooting.

The FBI is all about bullet penetration since 198x Miami gunfight.

I also ignore all energy figures. Math has created a problem no one is addressing. You get A number, period. That is how math works. So what does that number mean? All bullet styles get the same number in their caliber and weight yet can have vastly different performance in flesh. What do the differences in the numbers mean between the calibers? I propose that there is a line on a graph that says: to the left is inadequate and to the right of the line is adequate. More in not always either better or more effective on humanity. Too many variables. You are taking something hard and sticking into something squishy ( I know that sounds...)the human body, that can be vastly different physically and emotionally etc.
All calibers have success and all calibers have failures. The stories from the war and streets all have both truth and misinformation or are flat out wrong sometimes. Many police depts. report success and satisfaction with 9mm and some go so far as to say they cannot see any difference in the street performance between the different rounds.
"Old technology" bullets still show up pretty good in gel tests as they did on the streets. The same performance level wasn't always seen as the same with depts. across the country.

I've been reading and studying the "reports" on bullets performance for a long time now and I noticed the results are the same no matter who did the study. The 9mm is only 5% behind the best (read 45, 357 mag etc.) according to the authors. Is that supposed 5% significant? I don't think so as all studies have an error factor automatically built in.

What you shoot the best is what you should carry with the good ammo (you have to decide what that is) that you are comfortable with.

My joints don't like anything bigger than 9mm/.38 special for regular shooting anymore. I am very comfortable with either and that is what I carry. Plus, I agree with brucev above.