The ground hog is one of the toughest varmints to kill there ever was. We use to hunt them all the time as a kid on the farm. All I had to hunt with was a .22LR. But even using HP, many a varmint went back down the hole. Yes there would be a blood trail and after several weeks he would be out again. There was this one sucker who had his den smack out in the middle of an alfalfa field. Hard to sneak up on so shots were always 100 yds +. I had hit him several times. When I finally did succeed. he had 5 healed entry wounds.You are not going to kill one that easy.
Easier to get with a live trap baited with an apple. For some reason, they just can’t resist apples. The critters are very sensitive to heat. It would generally kill them by the time I got home from work. If not, then I`d drown them in the livestock tank. MUCH kinder and quicker than a .22 slug to the head.
'Course, I was using 80 grain pointed soft points in .234 caliber at almost 3000 fps. Turns 'em inside out, it does.
*Note: Sayin' I killed every one that I hit is NOT saying I hit every one that I shot at.