A good lever action rifle, aside from being a good hunting rifle is a good home defense rifle. A lever in .22 LR holds a significant number of rds… and a good .357 Mag allows for one type of ammo if you carry a .357 Mag 2 in or 4 in.
A .30 M1 Carbine… is an excellent firearm, but can be rather expensive.
Shotguns have always been good home defense weapons… and remain good defensive weapons…
Yes, an AR or an AK with a 30 rd magazine is good… but, if you can not find one or the ammo… a good 12 ga. or 20 ga. or even a .410 will work
If you want a pistol caliber carbine, try to match it with your choice of handgun. A Hi-Point 10 mm would be good, but 10 mm is expensive and if you purchased 1,000 rds of 9mm for your handgun, and only have 100 rds of 10mm, well.
Some of the carbines come in .45 LC, and some in 9mm… and even .45 ACP
With ammo scarce, it is a good idea to not waste any… and if you have lead, and a good flintlock, that works also.