Matt, I was using my .17 HMR and Sandy was using .22lr, Stingers specifically. She kept her shots under 150 yds, I shot between 100 and 200. One dog hit with the Stingers was hit it the stern end, the bullet exited his head. They did the job fine.
This particular pasture is only about 10 acres, and a centerfire puts them into their holes pretty quickly. That's why we use the rimfires. Not to get too graphic, but I hit one in the head at 150 yds with the .17, and it pretty much removed his head.
Oh, and around here I won't pick one of the little buggers up. They've already detected plague in them this year.