I used to shoot a few foxes in the late 70's with a BSA 243 for skins you had to shoot them in the head, used what ever projectiles that were in the shop. Use to blow their heads up a bit but usually got paid alirght for the skins.
But I used to go out with another bloke and he had a 222 he shot heaps all head shots paid for a land cruiser. This would have been pre 17 rem days. This shooter did get a 17 though I don't know wether he persisted with head shots though. Interesting in those days really the only target was the head.