At the risk of upsetting someone (as seems to happen around this subject),
what would be wrong with a head shot using 9mm from a carbine? Especially a JHP 147gr, shot only within one's individual and reliably tested capacity for reasonable accuracy? Of course that last bit is subjective. People have often wildly varying abilities to self-assess when marksmanship comes into the conversation. I've seen guys who declare their new gun 'scary accurate' when they can shoot a pop can sized group at 25 yards. Others for whom a 1/2" group at 50 is unacceptable, gets them wondering what's wrong with the gun. I got used to flawless accuracy early on in my middle-aged re-discovery of shooting, progressing quickly through a few airguns until getting a Pardini K10, easily capable of groups less than twice the diameter of the projectile at 10 metres using the worst Crosman pellets, and 7mm outside group measurement with match pellets. That kind of precision is addictive...
I'm considering using my TNW Aero on smaller deer (say, 350lbs and under) with shots placed in the mid- to lower-brain area, at ranges where I can ALWAYS put a shot inside a 1.5" (4cm) circle. In my testing so far, with just a couple of field tests using somewhat awkward placements resting my arm against a tree and on a rotten log with a bipod, that's about 40 metres. My heartbeat seems to be the biggest obstacle, so I'm working on stances/positions to eliminate that as much as possible. Not talking about front nor rear angled shots where glancing off tough parts of the skull are too likely - just side of the head, deer stationary, shooting only when certain that everything is ready. I'd rather have an unwounded deer run off than take an 'iffy' shot, same as for grey squirrels and rats.
This seems to be a controversial subject. I'm still not clear as to why. On squirrels with airguns I use an equivalent criterion and they drop every time. Just sticking honestly to the rules of one's own skill level and projectile power (between about 12 and 18fpe at point of impact) would seem to admit of 9mm being useful for smaller big critters, provided one is familiar with the specific anatomy in question.
Bella Twin's grizzly shot with a .22" Long round was well placed because she was a thoroughly experienced hunter and trapper in her 60's, someone who understood the value of a head shot. And it wasn't a "face-to-face" shot at all. From the thorough account I read, she waited until it was side-on presentation and quite close, not having spotted her nor her partner yet. 90 degrees to the axis of the bear's body. Right into the main part of the brain. She went on to load and fire all the rest of her ammunition, as she couldn't see enough to know for certain it was dead, but from the holes in the skull I'd guess the first shot was sufficient. That whole flat along the side of the skull between eye socket and ear is relatively fragile in most mammals. Wouldn't try it on a sheep, but I think most critters it'd work the same. A 9mm put right there would do several times as much damage. And remember, her old single shot rifle was a mess, held together with wire and tape, missing a big piece of the stock...