A squirrel hunting buddy calls the HM2 the ultimate squirrel round. We've used a couple of ours on prairie dogs. Even my converted Charger will shoot near 1" at 100 yards on a calm day. I think the rumors of the HM2's demise are usually started by guys who have never shot one.
Check this thread from rimfire central:
Look for my first 17m2 rifle. - RimfireCentral.com Forums
Sent you a PM.