I shoot a H&R Sportster in .17HMR. I have BSA's Sweet 17 mounted.
Hitting a Ground Hog out to 300 yards would not be a problem, even for a head shot. But, and a big BUT. The 17 HMR runs out of power after about 150 yards. Does not matter which bullet you are shooting, just not enough to be effective.
I let kids shoot clay targets a lot with mine. At 100 yards the targets explode into tiny bits. At 200 yards they break into large pieces. At 300 yards they will sometimes break into three or four pieces, but sometimes only in half. And a few times only a small hole through the target without breaking.
I have been thinking if I could hit one at 400 yards (would be next to impossiable) it just might bounce off the clay target.