Find him the right combination of carry weight, trigger pull, and accurate hits. If a .22 is what he likes best, don't worry. He's old and alone. His confidence level and skill level are more important than caliber.
Thanks, Obambulate, for reminding me of my mission here and for some of the reasons why I opened this thread. I have my own level of experience and background that, maybe in some peoples' eyes, would make them wonder why I even posted the situation my father is facing and its attendant questions. Just go with what I already know. The problem is that I've never encountered a predicament quite like this before and I'm trying to keep an open mind as to the solution.
Since I received my first gun (a Winchester Model 67, single-shot .22rf) on Christmas of 1957 when I was fourteen years old-a rifle that I still have, of course, and one that is headed for a lucky grandson or granddaughter on another Christmas day pretty soon-until the present time, I have accumulated a lot of nice firearms. There's not a bad gun among them (I'm no "gun snob", but I like to think I have good taste in firearms and I indulge in my obsession whenever I can find a little extra jingle in the jeans
). I have only one Taurus among the scores of Winchesters, Colts, Smith & Wessons, Brownings, ad nauseam (at least to my long-suffering wife of 44 years
) and I have that Taurus despite all the rancorous attacks from the "net" I've seen directed toward the brand over the past several years. I like to make up my own mind over these things and you can't make up a mind that is already made-up. So, as I said, I'm trying to keep my mind open to all advice I am lucky enough to receive. And, just because I may end up disagreeing with it doesn't make it wrong.
Four years in the military police and 26 years in le (which, of course, entailed a lot of "tactical" style shooting in training/qualification sessions over that period of time); serious Bullseye shooting competition and competing in Service Rifle matches over the past fifty years or so, has
not made me feel especially qualified or confident in choosing the "right" sidearm for use in protecting my dad (for instance, I started out thinking that a revolver would be the obvious choice for him and his situation. But then, some members made some good points about a semi-auto pistol as being a viable if not the best candidate for the role-which got me to thinking seriously about something I had already sort of arbitrarily waived off).
Lots of good suggestions recommending guns that, as already has been acknowledged, can never hope to perform the dual roles (ccw and hd) that only two separate and different guns can perform best. But one gun it must be and, despite all of the preconceived notions and baggage based on prior experience that each of us bring to the table as fellow human beings, I promise to continue to endeavor to keep an open mind as to any advice on this matter that comes my way.