You won’t lack for advice in here, but IMHO get a 20-guage shotgun and stoke it up with #4 goose shot. Won’t penetrate walls and punch holes in things & people in the adjoining apartment or down the street as much as a pistol bullet is apt to, but at close range where you need it, utterly devastating.
Psychological deterrent significant with a scatter gun.
Not many gremlins are crazy or stupid enough to stick around once they look down the barrel of your fowling piece.
A double barrel = intimidation X2, and unless you are going to train / practice intensively the simpler your action the better - and usually safer.
If you can’t settle a hostile home invasion issue with one or two rounds of #4 to center mass at 10 ft. (don’t let ‘em get any closer than that!) then call in an air strike; the war has arrived.
Don’t be hesitant or squeamish; mental prep critical.
A scumbag on bath salts is about as close to a zombie as you’ll ever hope to encounter; they have almost superhuman psychotic strength and it takes a #@!! of a lot to stop them.
A pistol - even a magnum - is a wimp compared to even a light gauge shotgun. The little .410 is more powerful than Dirty Harry’s fabled .44 Magnum, and it’s amazingly easy to miss even at close range with a sidearm, especially under stress. Look at how many cops shoot up a whole neighborhood before they manage to tag the bad guy - and they are trained!
Unless you are really emaciated or have crippling arthritis, you should be able to handle a 20 bore all right - but you MUST get competent training in defensive strategy, tactics, and the law - not just shooting.
Check with your local PD, Sheriff’s office, or shooting club for certified courses and instructors in your area.
Thanks for the replies so far, gives me a lot to think about. Don’t have any neighbors to worry about as far as other structures and I am not feeble. Hate to but a second shotgun we have a 16 gauge now. I was thinking a handgun would be a little quicker access. I am a decent shot and when it comes to our home I don’t think I would hesitate. I am half serb. Have shot many a 4 legged varmint over the years.
Here’s a site that looks at all sorts of ammunition. This page talks about the lack of penetration into a human with birdshot. And while #4 birdshot may not reliably kill a guy, I imagine it would deter MOST. However, after looking at his site (he has other pages with the testing results), I took out the #4 birdshot and put in 00 buckshot and slugs in my shotguns.