My carry guns tend to be shorter-barreled service/duty revolvers. 2” to 3”, or, a full-length service/duty revolver. Anything smaller is only an occasional gun, for occasions when/where something smaller is an essential factor, or, a secondary weapon, when carrying something larger. Compact handguns, that have small gripping areas, hurt my aging hands, so, I do not generally train much with them. It follows that I would rather not defend our home with a weapon with which I have less up-to-date skills. I do not have “designated home defense handguns,” but I may use what we could call an “enhanced” service/duty handgun for home defense. The chief enhancement would be a high-quality, rugged, weapon-mounted light, which means an accessory rail would be on the handgun. My Glock G17 pistols, one of which was one of my police duty pistols, before I retired, would be the leading candidate for the title of enhanced service/duty pistol. Sometimes, I carry a Glock, when out and about, but, not usually with a light on the rail.
So, depending upon where I am, inside the house, the go-to handgun that may be used for defense could be a short-barreled service/duty handgun, that I am already carrying anyway, a service/duty handgun, that I was already carrying, anyway, or an enhanced service/duty auto-loading pistol.
I do keep Benelli M2 shotguns, as part of the home-defense plan. One was my police duty shotgun, before I retired. (I was required to buy my own duty handguns, shotguns, and rifles.) If I have notice* that something serious is amiss, and there is time, I am going to have a shotgun in my hands. Nothing wrong with carbines; my shotguns had a head start, and I cleared countless building and built-up areas with a shotgun in my hands, while LEO-ing. My patrol rifle had to remain cased, in the trunk of the patrol vehicle, unless specified circumstances existed. Training opportunities with my shotguns were frequent, whereas training opportunities with the patrol rifle were rare. So, I am simply more comfortable with the shotgun. It is not that I am afraid that rifle ammo will “over-penetrate.”
*Multi-layered, four-legged warning is in place.