Isn't low recoil 9mm redundant? Wasn't that the reason lots of folks started using it instead of the much more effective.45 acp?
Or a better question, what has happened to the toughness of human beings?
My opinion why lots of folks started using it was the much lower cost, and much better availability of both ammo and pistols on shelves.
The toughness didn't have anything to do with it. I'm a 45 guy, mostly carry either a 1911 or S&W M&P Shield 45....but you can't deny the increase in firepower with a 9mm and with the better rounds today terminal ballistics are pretty dang close in ordnance gel testing.
I was fresh out of SAMI School and assigned to Station Weapons Range/Armory Division when the transition from 45ACP vs 9MM was happening. I was in the 45 camp for sure.....but then we were held to FMJ only either way. These days.....the modern ammo has evened the field for civilian use. In my meaningless opinion of course.