Another critical piece of information for home defense: Ballistics
Best personal "gun" defense is spelled B-A-L-L-I-S-T-I-C-S. Whether it's practice at a range or money sunk into professional firearms training and qualifying, your best home defense will only be as good as those defending it and their knowledge of how to efficiently and immediately incapacitate their adversary.
It doesn't take years to acquire, maybe just a couple hours of research and comparison, but understanding the effects of a bullet upon entering the human body will help you make wiser decisions on what to select for home defense.
It basically boils down to this: the HEAVIER a bullet weighs, the DEEPER the penetration and the HIGHER the chances [efficiency] of IMMEDIATE INCAPACITATION. It is NOT VELOCITY that accomplishes penetration. However, they BOTH work hand in hand.
I'm a firm believer in defending what is rightfully yours and using whatever means are necessary to defend, including taking the life of an adversary posing as a threat. The only way to do this, however, is be sure that whatever means you are using to defend with WILL exact your expectations rather than disappoint them.
In the line of handguns, I've come to the conclusion that the one suitable for this scenario is with a .45 caliber. I believe the .45 AUTO has a 260 grain load too (highest I've even heard of for .45 but I don't think these are ACPs). The current standard is 230 grain (weight of the bullet) for .45 ACP and that should be sufficient for getting the job done. Every other caliber smaller than a .41 Remington Magnum is around 10mm at 205 grains and it just goes down from there. The BARE MINIMUM that ANY bullet should weigh for self-defense is 125 grains. There are countless stories of police that have responded to a narcotics scene with armed men in a car opening fire and killing two or three police, themselves being wounded by four or five 9m bullets in their backs still able to function and operate a gun. Home defense is NOT the same as range or practice.
At this point, notice that the emphasis in all this information is NOT one gun over another. Guns never killed anybody other giving someone brain damage being used as a clubbing device and if I could put together a small contraption that has a metal bore tube with something to hammer that primer in the back of the cartridge with, I'm sure somebody could get hurt if pointed in the right direction. Bullets are the killer whether it's in a Jennings or a top of the line .22 revolver. Whatever
You should also take into consideration the efficient expansion of that bullet as not all bullets expand very well. Jacketed Hollow Points (JHP) expand a little more reliably than Round Nose (RN) and from there you can get into the lead, etc etc. Why is this important? When a bullet enters the human body, it begins to expand. You can see the same effect throwing Play Dough onto the concrete, only here we're talking about a much harder substance, usually lead. As it begins to expand, physics of course takes over, that bullet is not as smooth and pointed as before and as the overall front surface area increases, the bullet will begin to decrease in velocity until it comes to a rapid but complete stop inside the body of a human body. Heavy clothing can sometimes interfere with penetration as the bullet will begin to expand prematurely upon hitting hard metal objects or material. Hence life saving stories of people having coins in their shirt pocket or a Bible that stopped a bullet and saved their life. The bullet expanded prematurely and was unable to penetrate deep enough (if at all) to damage any vital organs.
Always remember that if your motive behind having a gun at your bedside at night is to be able to defend your family in the event of an intruder seeking to harm the life of either yourself or your loved ones, once that gun is drawn on your engaging threat, you shoot to kill. Always. Anyone who has ever shot to negotiate or shot to injure or shot to temporarily incapacitate someone just long enough to put the dog leash on them is probably either dead or in jail to this day.
The key to immediate incapacitation (which is ultimately your goal in an emergency life/death home defense situation) is penetration. This is the only way you will be able to defend yourself. Not by spraying them with Bear Mace or messing around with "dummy" loads (those are loads that dummies use in their magazines when they care more about their adversary's life than that of their own family's).
Realistically, it will take more than just one round to accomplish immediate incapacitation, even with a .45 because not everyone is that perfect of a shot (unless you're Bob Munden). Observe all safe gun handling rules, do what you need to do if you are genuinely in fear for your life and just be ready to show up in court when Uncle Money shows up to press civil charges because you shot their nephew who was on their way home from feeding the homeless and "stumbled" into the wrong house. Find you a lawyer before hand (in other words, before anything happens - as in while you actually have a clear mind to think; could be today, tomorrow, this week, preferably sooner than later) and ask if they handle firearms cases. If so, try to find you one that can educate you on what you should and shouldn't do under certain circumstances and scenarios. Come up with questions and a bunch of scenarios you may find yourself in and ask what sequence of events must take place before you can pull out your gun. You may find some disagreeable information but that's
Hope this helps. Ballistics will certainly help you in making a decision on which gun to have on hand for home defense. So will practice on the range and safe gun handling techniques to make sure you can quickly and efficiently draw your gun without sweeping others (that is, the direction your gun points as you bring it on target) or putting other innocent bystandards in danger.
Remember, with great power comes great responsibility. Know your gun, your environment and your local, state and federal laws. I think that's the best home defense you could possibly have is someone who is well trained, ready and able to defend, having understood the consequences of their actions with whatever gun they own or decide to use.
Hope this helps!
Matt