Prarie dogs (which is really where it shines), woodchucks, rabbit, crow or any other small to medium sized critter you want to whack with it.

Many use it for fox and coyote as well.

I personally think the HM2 is a better tree squirrel round, I may have to get me one.

Basically about anything you would use a .22 mag on. It shoots a bit flatter and is inhearantly more accurate in most guns. You can buy a fairly cheap (160-200) marlin or savage and get 1 MOA out of the box or better in most cases. I think the .22 mag does have slightly more down range energy though do to the heavier bullets. However the .17 bullets perform VERY well in game if you pick the right bullet for the job.

Paul