I have tried a calling set once or twice for them but most of the time call for yotes. From what I have gathered here is the difference in calling for cats.
Cats tend to take longer to come in and will turn back around if the calling stops for very long. Also, they seem to be pushed more than called in when the calling is too loud. So call for 45 min to an hour and a half in a good area. With an ecaller is better if you don't want to run out of steam calling for so long. Turn it on loud enough for the sound to carry but not too loud to blow them out of there. Keep a really good eye and keep your movement to a minimum. They will hang up in brush or on edges and just stare for hours if they get close and don't see whats making the call.
As far as caliber, I would shoot an open choke shotgun with#4 buck shot if its in close. If you think you will have longer shots then any 22 cal rifle should do the trick with a v-max style bullet.
Again, I don't have too much experience first hand, this is just info I have gathered from others.
