I would rather use my .12 auto with .00 buckshot versus my .9mm auto or my .357 revolver.
Come on John, WTF is a
.12 auto? Do you really own a
.9mm?? Check your spelling you look like a noob when you don't use the proper descriptors for your firearms.
It's a 12 gauge, no '.' in from of it. Same with the 9mm, it's not a .9mm.
AR is an outstanding defensive weapon, home or anywhere else. It is also not an 'assault rifle' that is just liberal fear labeling. For it to be by definition an assault rifle it's got to be select fire. The ARs you buy today are just modern sporting rifles (unless you can afford $25K+ for a pre 1986 NFA one, or other designs).
Those rifles can be easily operated by even small stature individuals, unlike the more powerful battle rifles. They are relatively easy to learn and obtain a moderate level of competence. Reliable, easy to maintain and until the past year inexpensive to feed.
Semiautomatic, magazine fed rifles have been commonly available to the general population for 110+ years now. Only in the last half of that has the time frame has the intermediate (read: less powerful) calibers gotten popular.