What sidearm we choose to do so with is up to us.
Certainly.
But to say "it works" is meaningless, if we are speaking of defensive use. We can only know what
has worked if we have used it, and then, only that it did work on that occasion.
And by far, the preponderance of the evidence is that
today, a high-cap service auto (with higher capacity than the one I carry) is, for SD,
far superior to any revolver, assuming the user is trained. To insist otherwise is a form of denial, in the nexus of fantasyland and frontierland.
For a working rancher in Idaho in the 1930s, different considerations applied, and the guns that could be had were different. Colt still listed the SAA. The first large capacity semi-auto did not come into being until 1935, and it was not chambered for a load that many ranchers would likely choose.
Elmer Keith preferred revolvers--big bore revolvers--for work, for sport, and for load development.
An interesting aside: When I was new to hand-gunning, most of my friends were looking at the Colt .45 "Government Model", or at DA revolvers. I decided I wanted a Smith and Wesson Combat Masterpiece revolver. However, military demand made it unavailable at the time.
I ended up buying a 9mm Smith and Wesson Model 39 in 1966.
I did so at the strong recommendation of a very well known gun-writer--Elmer Keith himself, who had written about it in
Sixguns by Keith.
Today, for CC, I carry a semi-auto. I have never had to use it, but I have trained with it. I do not contend that it is the best choice, but I can carry it all day and I can shoot it.
If recreational hand-gunning were still something that I could reasonably do, I would not use the semi-auto. I would use a belt revolver.
Can't say what kind. Maybe a .44 Triple Lock. Maybe a New Vaquero.
But not with loads that would impress Elmer.