There are variations of 9MM. The US commercial 9MM is the wimpiest on the planet.
The NATO Spec 9MM is a whole different ballgame. Every round of NATO 9MM is at the low range of US Proof Rounds for 9MM.
That is why the technical feasibility tests for the 9MM handgun candidates had to be dropped from 10,000 rounds to 5000 because the first 9MM test at Aberdeen had all the candidates go down between 4000 and 6500 if I recall them rightly.
9MM fired from short barrels has a lower velocity. When 9MM really shines is when it is fired from a longer barrel like a SMG or a MP5.
I once did a rather involved test at FLETC. I got 357 Mag ammo from all agencies had in their bunkers and chronographed it from 3", 4", 6" handgun and Marlin 1894 rifle with a 18" barrel. If I run across the data I will publish it but as I remember the average velocity enhancement was like 275 FPS and there was one round that was near 400 fps increase from shortest to longest barrel.
There was a round developed at Aberdeen that would punch a IIA from a 5" barrel at 100 yards! ! ! ! ! I asked the designer what the estimate was from a 357 Magnum and he figured 150 layers of Kevlar or maybe 6 or 7 vests. That design weighed about 95 grains..
