For a Kel-Tec Sub-2000. We’ve said it before: the Sub-2000 is an excellent home defense weapon, especially for smaller-framed people (i.e. many women) and the elderly. It’s light and easy to aim; easier than a handgun and a lot easier than a shotgun. There’s minimal recoil. 9mm bullets are relatively cheap (encourages practice). You can fold the Sub-2000 for easy storage and extra safety (you can lock it into the folded position). It’s not as deafening as a shotgun. And it accepts all Glock magazines, including ones that hold 30 or more rounds. Why would you need so many bullets for a home defense carbine?
Because you might miss and there might be more than one bad guy (three assailants would yield ten bullets per perp).
Also, expecting a non-combat trained defender to carry and then change magazines mid-fight is ludicrous. And no one ever ended an armed confrontation saying “Damn! I wish I’d had less bullets!”
Wait. Is that one reason or a few?