Groundhogs are almost a thing of the past around here. You still see them, just not as much. I'll shoot a few every year, usually with a 22, around or in buildings here on the farm. I might see one or two in a beanfield, but for the most part they've moved to places where it's more difficult for the coyotes to find them.
This is my experience too.
Darrick your post reminded me of trying some40 gr. sx in my old22-250 years ago trying to generate. 220 swift velocities. The fiocchi must be a little tougher as I would be getting a good group and then miss the target completely. I did the check the scope thing a bit of head scratching then my buddy wanted to try. I was watching him shoot and on the 3 or 4 shot and saw a streak come out of the bbl at the shot. Yep problem solved bullets were disentigrating. Back to 50-55 gr and everything was roses again. Hard to beat a 22-250 on groundhogs.
