Originally Posted By: basdjsI've hunted Pa. groundhogs often for several years with .17 HMR, .17 Hornet, and .17 Fireball. The HMR is my least favorite and I've stopped using it due to crawl offs. I've had no problems with the Hornet to about 200 yds and to 300 yds with the Fireball shooting 20 gr v-max in the vitals. You may have an occasional one kick down the hole if sitting on top of it, but most are tail straight up and DRT. The 25 gr v-max or HP work fine too, especially if you may be hunting coyotes with the same rifle. A 20 gr on a coyote tends to splash if you hit bone. I would tend to agree with distance's and cartridge's, for Ghogs. When I was shooting my 17fb it wouldn't shoot the 25 or 30 gn bullets as accurate as the 20 vmax so I stuck with the 20's. I wanted it to be my fox gun but it just didn't work as well as I had hoped.