I have shot a lot of foxes with a 222rem, nearly all with 50gr Vmax handloads. I would not use 55gr SP's in a 222rem, velocity will be under 3000fps and most bullets will exit. The 50gr vmax loads should be around 3100 fps, these kill very well and rarely exit, much safer. I have used 40gr'ers, brillant on rabbits and kill foxes very well, but blow about at bit in the wind.
The general advice is good, if not entirely accurate. Zero around an inch high at 100m, you should be spot on at around 160 - 170m and a little low at 200m, maybe as much as 2" low.... If you are lamping 200m is a very big shot no matter what any one says and you will rarely need to shoot that far. Daytime is obviously different.