Ruger
I've got my Dad's convertible Single-6 and keep the .22 Mag cylinder in it. I never really had anything good to say about .22WMR, but when Dad's pistol came my way after his passing, I put the mag cylinder in as a novelty, since I had all the .22 lr pistols I needed in a MkII and a Bearcat.
I was immediately impressed. The mag seemed to hit and kill appreciably harder than any .22 lr round out of a hand gun. This is on 'dillo's and coyote, rat's, etc. Dad's pistol has a tad longer bbl than I normally carry, and I shoot it better resultantly too.
My std load is Win JHP, occassionally FMJ. The hi-vel light bullet stuff and other mfg's std bullet weight ammo will not get to point of aim, even w/ adjustable sights, but the Wins will. And the FMJ and the JHP (in the Wins) shoot to POA in the revolver.
The .22 mag ammo has gotten expensive, and I do not shoot it as much as I used to, but its still a great round./combo