One guy I used to work with in Wyoming used nothing but a .22 Mag - - of course, he hunts with dogs, and the "lion's share" of his shots are on treed cats within 50 yards. Another guy I work with drew a tag and was lucky enough to get on a cat (I say lucky, because we cannot use bait or dogs here in SD). His son spotted it first and winged it with a poor shot from a .22-250, and the Father was lucky enough to get a shot with a .270, which put an end to things. That .22-250 would have been sufficient, had the shot been placed properly.
Locally, there have been four long tails shot within the last three weeks - - two within our city limits, one within the city limits of a nearby town, and one just on the edge of another nearby town. One of the cats shot here in town was killed by a RCPD LEO with a .40 - - but given the way our local LEO's shoot, I reckon there was more than one round fired to dispatch that cat. Haven't heard the details of the other three cats.