I'm surprised to see so many guys convinced that a 12lb fox is THAT MUCH TOUGHER than a 20lb turkey? Many of the load/choke combos out there now are easily 60yrd turkey weapons, after swatting feral cats at 50-60yrds with my turkey gun (Benelli Supernova, Tru-glo Gobble Stopper choke, 3.5" Winchester Supreme High Velocity Turkey 5's-now called "Double-X"), I'd be hard pressed to say it wouldn't work well enough on fox too.
BUT....
I personally wouldn't be excited about using turkey loads for fox, mostly because I don't really see a reason to do so? #4 buck loads are readily available, and they're not any more expensive than turkey loads, so I guess I just don't see why you'd use turkey loads?
_________________________
Conservationalist? I thought you said conversationalist!?!?!