A revolver is a good first choice and may be easier to practice with.
Having an AR-10, AR-12, AR-15, etc. works depending on the house layout but may be a lesser choice if you can't get enough practice with it. One problem with a long arm is that you may not want your neighbors to see you transporting it to and from a range whereas a handgun is much easier to avoid detection.
Yeah, I kind of misread the post.
IF it’s just to fill a “home defense only” gap, I’m definitely a big fan of shotguns. With pistol grips, and 18-1/2” barrels, for maneuverability. And a light on the end, with palm pressure switch, to activate only when you want. The light beam primary focus circle should be about the size of the pattern.
If you can handle it, a 12 gauge pump like the Mossberg 500 with pistol grip.
For women and elderly, same gun in .410(!). Why? Super easy to handle, rack, swing from the hip and fire, practically no kick, and IIRC, the .410 00 buck has about the same enrgy as a .44 magnum. Which is plenty for in the house.
But for the 12, #4 is better indoors, imo. And BB shot—just a bit smaller than #4 buck—can be bought for 50 cents per in bulk. Sometimes less. That’s good enough for indoors, as well, from a 12 gauge. Lots less kick than 00, but will still remove limbs at in-the-house range.
Practice shoooting it from the hip. Pistol grip that is. Super easy and fast, hard for the bad guy to grab. I tend to shoot a bit low like that. Oops.
Hehee.