It depends on the bullet configuration. The class round-nose FMJ is actually a very poor self defense round; while it penetrates well, it "slips" through human tissue without really doing much damage, unless you hit something vital dead center, like a spine or brain.
Of course, if you're in a populated area where overpenetration is a consideration, it's a different ball game.
Anyway, what you really need for that "punch" is a FMJ with a flat point, like this one at Buffalo Bore:
https://www.buffalobore.com/index.ph...ct_detail&p=69
The flat point tends to "crush" tissue as it plows through it, and does great damage, while still penetrating both the bad guy and the car door he's hiding behind.
On our ranch out here, I carry the BB 9mm +P+ Penetrator ammo which is designed the same way. You can kill just about anything with that bullet.