Hi,
Welcome to the forum, and I'm gonna take the "High Road" here, just as we desire to do.
Thus, I'd also like to welcome you to the shooting sports, for your questions indicate you are a novice and (possibly) your forum name may indicate you live in a very large city at the bottom of a beautiful state not known for having any big game in it that far down.
If this is true, your hunting needs might be for small game, with an occasional alligator threat. Thus, no need for a .308 "deer rifle" here! On the other hand, if you plan to travel to other states to hunt (and my state of Georgia is currently overrun with Florida hunters who have memberships here), a .308 is a decent deer cartridge.
In the "urban jungle" of Miami though, a .308 bullet flying through the air is a disaster/lawsuit/prison sentence just waiting to happen. I seriously doubt the LEOs in Dade County would be using rifles down there any more potent than a .223. As the late gunwriter Jeff Cooper always said, a .223 bullet makes a great "poodle gun" or to shoot enemy soldiers who really don't want to fight anyway. I could surely be wrong, but I doubt even the sniper team down there uses a .308.
Thus . . . if you live in Miami, a .308 is not what I'd own for "defensive purposes." Heck, here in the rural parts of Georgia, most farmers would use a shotgun for defense rather than their deer rifles.
ACTUALLY . . . a shotgun IS your best defensive weapon! Always has been! It doesn't overpenetrate walls of homes, you don't have to be THAT accurate with it, and most bad guys crap in their pants at the distinctive sound of a 12 guage pump shotgun's slide being racked!
SO . . . forget the rifle, period, and get a 12ga. pump shotgun! They are cheap but VERY good at a lot of things! It CAN be used, with the appropriate shot load, to take ducks, squirrels, dove, geese, DEER, bear, etc. It is VERY deadly on wild dogs in a neighborhood . . . but the pellets lose effectiveness rapidly after 50-60 yards or so with most type of pellets. Thus, it is as "safe" an urban power gun as possible.
AS FAR AS A PISTOL GOES . . .
The "which caliber is best" debate will never be settled. Some think the 9mm is a good cartridge. These folks are
generally NOT big game hunters but mostly city folks who haven't taken game before. The 9mm hardly kicks at all . . . and you can load LOTS OF BULLETS!
However, bullet placement is key to incapacitating any game or predator INSTANTLY . . . and this has nothing to do with lots of ammo but EVERYTHING to do with markmanship, skill and experience.
If one has to shoot a target many times to stop the threat TWO THINGS are more possible . . .
1. The bad guy may shoot you with a fatal shot (or several) from HIS 9mm before he bleeds out and dies. Thus, you are dead too! NOT GOOD!
2. There are more stray bullets flying in the urban jungle . . . all capable of punching through wood and sheet rock walls or car doors and thus possibly causing you to accidentally kill or paralize an innocent person. NOT GOOD! You may win the gun fight, but end up in jail for years convicted of a felony murder charge. Also, the family of the innocent one will sue you out of everything you'll EVER dream of making. NOT GOOD!
MY RECOMMENDATIONS . . .
If you INSIST on an automatic handgun (which seems to be the latest fad) . . . spend some serious bucks and get one that NEVER, EVER JAMS! When you find that one . . . please let us all know . . . for no one should ever bet their life on a gun that MIGHT ever jam!
Your safest bet wouldl be a Glock. Jams are rare but they WILL happen! Also, buy at least 500 rounds of ammo and run those 500 rounds through the new auto to smooth it out, familiarize yourself with it, and most importantly, MAKE SURE IT NEVER JAMS ONCE! If it does, keep running ammo through it until you know it is broken in well and won't jam!
FIVE HUNDRED ROUNDS costs money, so factor this into your budget.
INSTEAD OF A 9MM . . .
Purchase at least a .40 S&W. With the best hollowpoints, the .40S&W round has the effectiveness (almost) of a .45 auto OR the legendary .357 mag. REVOLVER.
As I mentioned earlier, you want to hit your target ACCURATELY . . . and have that target INSTANTLY stop fighting you. There are never any guarantees though, and even those these calibers can't guarantee you of 100% instant stop capabilities.
HOWEVER . . . SKIP THE JAM-O-MATICS FOR NOW!
You are a novice who has a lot to learn about trigger control, accuracy, how to clear jams, how to clean guns, where to place bullets into living game effectively (game . . . and bad guys too . . . don't stand still like targets so you can kill 'em . . . they ACTUALLY try to avoid being shot!)
INSTEAD . . . save a ton of money and get an easier to use, easier to master, more powerful and safer S&W revolver in .357 magnum! Yep, get a used one in good condition. They don't jam, they incapacitate bad guys better than anything else statistically, and they are easy to unload and keep safe.
Also, under stress there are no levers to forget to operate. You'ld be amazed at how many people get killed because their gun won't shoot and thus end up with the bad guy calmly putting a bullet into their brain at three feet. All that was wrong, is the safety was still on! That can't happen with a revolver. As the old saying goes: "SIX FOR SURE!"
FINALLY . . .
As someone mentioned . . . get some really good training. A city-boy friend of mine from Indiana took my advice and paid instruction with a certified NRA instructor before even buying a handgun. The instructor taught him safety . . . but also proper grip, stance, sight/eye alignment, all the subtle trigger finger control movements that most untrained shooters do wrong (and thus can't shoot a handgun accurately). The instructor also took him to the range to shoot a lot of types/makes of revolvers and autos to find the one that best fit his hand.
The result? My friend bought a handgun that fit him like a glove . . . and quickly learned how to shoot really tight, small groups with his new gun. Rather than just another city-boy yahoo with a handgun who can't hit the side of a barn, I wouldn't mind having him by my side if the SHTF!
Good luck and . . . if you follow my advice like my friend, two things will happen that I initially warned him about:
1. You will become a super shooter!
2. You will become addicted to shooting sports and soon have a bunch of guns that you shoot well and have fun with!
T.