I hate to disagree with my esteemed colleagues here and I realize that the Mini-Master is absolutely NOT an ideal hunting revolver. That aside, I've actually had pretty good luck with mine. I've reliably taken squirrel, dove and rabbit with it but never at anything like 25 yards...I doubt that I'd take that shot at a squirrel with any but the most accurate pistol.
Here's a decent review where the author managed 2" average groups with .22 WMR
http://www.naaminis.com/news43.pdf
If I really concentrate, use a steady rest, and Jupiter's moons are in perfect alignment, I can keep my 5-shot groups inside 3 to 3.5 inches at 25 yards. I've read the accounts of others and I know that my Mini-Master is the exception rather than the rule as far as accuracy goes because I'm not the greatest pistol shot in the world. In fact, my wife is rapidly becoming the best pistol shot just in my house.
This is just my woodswalking gun and only because I can't find one of the ultra rare S&W 3" stainless .22 WMR kit guns that had a second .22 LR cylinder fitted at the factory. If anybody here has one and needs a kidney or lung, let me know.
I would echo the suggestions of others here regarding a dedicated small game pistol...you can't go wrong with a Ruger pistol OR revolver.
Also an echo...rimfire shotshells are worthless for hunting unless you're stealthy enough to get within muzzle-contact distance.