Let's see. Brown bears differ in size.
Guy in this picture is 6 feet tall. These are russian bears.
You sound like a police officer, or mil, so carrying a full auto 9mm might be annoying enough, and quick enough, to turn a bear, but, it might also just piss them off. Hitting a bear with a half pound of lead, or jacketed bullets, in full auto, might deter the attack. I assume that's what that 33 round mag is for, a selective fire handgun?
A word about Penetration. I have a .510 Linebaugh Maximum, that shoots 525 grain bullets, at up to 1550 fps. Yes, it is the most powerful handgun in the world, S&W jive to the contrary. That generates about 2600 ft-lbs of energy, and, about 52 inches of bear penetration.
You can download that same bullet, to say, 1100 fps, and have it be MORE effective then at the higher velocity, with the same penetration. While no bears, this round has been used on bovines up to 1600 pound asian buffalo, with devastating results. These bullets hit with about the same effect on cape buffalo, etc. as a 375 H&H rifle.
That said, in our area, two monster bears, read 12-1400 pounds, both took 11 rounds of 375 H&H, before going down.
S&W guys are using a 700 grain bullet, but, stabilizing it can be a problem:
http://i45.invalid-sanitized.localhost/albums/f99/Socrates28/Familyportrait3.jpg
.510 Maximum, target grade accuracy .475 Linebaugh, done on FA 83 by Jack Huntington., 45/454 Seville done by Linebaugh/Huntington, 45 Supers, and 357 snubby.
I'd carry one of the smaller guns to stuff in the bears mouth, after the 9mm didn't work. OH, my smallest gun
has ballistics equal to, or superior to your 9mm, and, I think that's just a stop the pain gun after the bear gets to me, or, at least disrupt his dinner with a little lead in the teeth.
My point simply is that your idea of a 'deep penetrating bullet' used against humans, becomes a shallow penetrating bullet, or no penetration, on a large brown bear. I've never heard
of a 9mm bullet coming even close to these guns in penetration tests, and, they can certainly be turned by a large browns bones.
http://www.handloads.com/misc/linebaugh.penetration.tests.asp
If you look at the above tests, the closest you come to 9mm is .38 special, with 8" of paper penetration. Giving
it a big boost in speed, figure maybe, it will go 16" in newspaper, and bone. The .500's give you about 4 FEET, or 48-52" inches, with hard cast bullets, or solids. The .475's are no joke, and, the 44 or 45's with 325-360 grain flat nosed bullets will go 38" inches of cape buffalo. Observed hits on bovine indicate the big bullets are REALLY noticed, and take affect, and may turn, and get the animals attention.
I hope your gun goes full auto.
S
PS
Another alternative is a Ruger #1, in 510 Wells. That's a 6 pound rifle, with a blown out weatherby 460 case, to 510.
It will recoil enough to knock you out of the bears path, and, if you hit the bear, it's going to knock him, and you, down, at the same time. Chances are, he's going to get right back up, but, at least you'll have time to aim, perhaps reload, and hit him again. My point is, in a bear charge, you need a rifle that will hit the bear hard enough to knock him down, so you can place your second shot, accurately. A double rifle, starting in 450 N2 is the starting point, and, the 458 Lott is the most economical
stopping rifle going. People also hotrod .458 winmags, and, with 500 grain bullets, at 2150 fps, they are starting
stoppers. Shotguns just don't have the penetration, or energy, to really knock down a bear.
PPS
IIRC, the 9mm that broke the 'bear's' leg, was on a cub brown bear.