22-rimfire, that was 35 years ago when I had better eyes and a steadier hand.
My childhood home had a front porch that was right at 200yds away from a ground hog hole in one of our hay fields, I would sit there and wait for the critters to come out and get away from the hole. I would make a noise to get them to stand up and I would hit them between the eyes. I do not recall ever wounding one and it going back in. A 200yrd shot with CCI Stinger required me to aim about 4-6" high
I agree in not wounding animals, their death should be fast and painless. Of course as a 12 year old kid back then it was about killing groundhogs and collecting the $1 a hog bounty my dad put on them. I cant remember how many cattle and horses we had that were injured stepping into groundhog holes, not to mention when you hit a hole with the tractor it would almost throw you off and under the rear tires. They were a nuisance.