Lone Wolf, I have had mixed results with well over a dozen hits on coyotes with the .17 HMR "standard" round, the A-17 "hopped up" one, and also the .17 WSM (all rim fires).

My thoughts: use the heavier bullet choice in each caliber, keep under 100 yards, and try for a broadside BEHIND THE SHOULDER heart/lung shot.

It's been said before, and will be said again, coyotes are TOUGH.