I have handled firearms for nearly 60 years now. My friends who know this often ask "What gun should I buy for self defense?" The question always makes me wince, but I get it often enough that I have decided to explore the topic with you. To answer it honestly, we will first have to cover some important ground. Do you really need a firearm for home and/or self defense? Well, probably not. Unless you live in a bad neighborhood, the odds of your confronting a dangerous attacker are pretty small. I have a permit, but almost never carry. I just stay out of known dangerous areas.
For sake of conversation, though, let's assume that lightning may strike. Are you going to be comfortable using deadly force? You can't shoot someone "just a little". Human bodies are packed chock full of important structures. When a bullet punches through, it is almost certain to maim, and very likely to kill. A bullet strike is going to do major damage. If you don't believe that a man who is bad enough to be shot is bad enough to be killed, then defending yourself with a firearm is not for you. This requires a certain mindset.
Many deadly encounters occur in dim light, or none at all. Are you cool enough to positively identify what you are shooting? Always? That "intruder" could be your child or spouse. Real gunmen are not trigger happy. They will fire only if there is no other option. You can legally use deadly force only when you honestly believe that your life is in immediate danger.
Should, God forbid, you ever have to shoot someone - call 911 immediately, and then put your gun down before the police arrive. They can't know who is good or bad, and will be in fear of being shot themselves - so make very sure that they see your EMPTY hands.
For a firearm to be useful, it has to be handy. Having one loaded and within easy reach raises the very real possibility of unauthorized access. Firearms attract both children and unskilled adults like a magnet. Years ago, I had a little Colt lying on a table beside my chair. A friend, who was enrolled in graduate school at the time, walked into the room, said "Oh! A police revolver!", picked it up and snapped it several times. How happy I was that I had not loaded it! This young adult, who was far from being an idiot - but unfamiliar with even elemental firearms safety - put us both at risk in the blink of an eye.
Don't assume that because you have taught your kids how to handle guns safely, that you can leave them lying around. They have friends, who are likely to be as ignorant as mine was. If the piece is not on your person, it needs to be locked in a case. The greatest risk of firearms ownership is unauthorized access. Read that again. Tragedy can result from this - and often does. I cannot emphasize the danger enough.
Nobody knows how to handle firearms safely until they are properly taught. My father drilled firearms safety into me, when I was a boy. If you are not so lucky, get competent instruction. Most avid shooters are very happy to mentor a novice, and most shooting ranges offer safety courses. Don't be embarrassed to take one. None of us were born knowing how to handle guns. We were all taught. The raw basics are: always assume that the gun is loaded and ready to fire - and never, ever, point it at anything you don't want to destroy (an old gunman navigating a crowd will have his muzzle pointed straight up or straight down). Keep your finger off the trigger until you are ready to fire. Never trust mechanical safeties. Owning a gun demands that you learn how to use it safely. This isn't difficult - millions of shooters before you have mastered the art, and you can too. You just can't skip this step.
OK - you have decided to get a gun, you are going to learn how to handle it properly, and you are going to LOCK IT UP when it is not in your possession. You have a cool head, and you understand the absolute need to always positively identify your target.
So: What gun should I get?
Most people who ask this question are thinking of a pistol, which is certainly the handiest choice (and the only one if you plan to carry) - but also the one which requires the greatest attention. A flick of your wrist can swing the muzzle through a sixty degree arc, and if you hold it carelessly, you may find it pointing at your femoral artery.
Your first pistol should be a double action revolver, with a four inch barrel, like our police used to carry before they switched to "automatics". Self loading pistols, and the old "cowboy" single actions, require more thought in handling and use. Leave them for their aficionados. With a double action revolver, you just pick it up, point, and pull the trigger. Nothing to think about. That's a good thing in high stress situations! This also means that a double action revolver is the safest pistol that you can own.
Any caliber larger than the .38 Special is going to rattle a novice with excessive recoil and muzzle blast. Get a .38 Special, load it with standard velocity ammunition - avoid the hot +P stuff - and then take it to the range and learn how to shoot it.
For strictly home defense, you can also make a very decent case for the shotgun. The best defensive shotgun is a short barreled, pump action "riot gun". Store it a with a full magazine, and an empty chamber. Racking the slide to load produces a quite distinctive sound which will chill the blood of anyone who recognizes it. A shotgun can be clumsy in tight spaces, but it provides intimidation in spades. Birdshot is fine for self defense - and is devastating. There is no need for buckshot or slugs.
Forget about rifles. They will shoot right through walls, and endanger your neighbors. Leave them to deer hunters and our military.
Are there alternatives to firearms for self defense? Sure. How about a nice baseball bat? Or an old machete? Such simple tools might actually be better choices.
In fact, all of my own firearms are locked in a steel safe. If an intruder broke in, I'd have to say "hold on a minute, let me find my key - and damn, where did I put that ammo?" The point being, I think that "self defense" worries are much overblown. My children are grown and "firearms safe", but they often bring my grandchildren to visit. The risk of unauthorized access simply outweighs the benefit of readily available deadly force, which is why I bought that safe. I'm an old gunman who doesn't keep a gun for self defense.