I like both the K-22 and Ruger MKII for handgun hunting and serious paper punching. But my favorite .22 revolver for trying to become a better and better shot is my S&W M63. The little four inch J frames are much harder to shoot well than a larger frame gun. I was hitting all over the place with mine when I first brought it home. But a lot of range sessions has smoothed that out. A smaller gun isn't forgiving. You hold it a different way every shot, you don't get groups. You don't execute the trigger pull the same and deliberate way each shot, no groups. You don't really bear down and watch every molecule of that front sight, no groups.
It's a trainer par excellence. I shoot more rounds through it every month right there in my driveway than any other gun I own.
Gregg