Maybe it is just my experience and how I place my shots, but my .222 is more prone to tear up a Fox than my .308 is. Just don't shot them head-on, in the gut, or moving away (straight in the ass). A quartering shot or a side shot through the lungs rarely does any major damage. I shot one Fox pup about the same size as a Cat behind the shoulder, hole in hole out. Where I've shot Fox and had the .222 hit a rib or something change directions and pretty much explode the Fox.