More than fifty years ago, I got the regular job of clearing feral cats from a chicken farm in the Transvaal. At the risk of being run out of town by you serious powder burners, I admit I used my old Walther PP Sport target pistol in .22 (shades of James Bond). I could slide it under my jacket if the children or visitors appeared. It was pretty easy to sort the farm cats from the feral - the farm cats ignore you but the ferals get snarly straight away and don't back down. You could walk almost up to them and they just snarled louder. I drilled my .22s with a 3mm drill bit and packed them with vaseline...those were the days. Needs must. They worked well and never needed a second. All head shots, mostly straight on. A word of warning. Don't try to pick up a freshly dead feral cat, even by the tail. I swear the blighters can come back from the dead for a last go at you. They are seriously tough creatures and amazing ambush predators.