Ok mate firstly .222 are a good,very very accurate round(better than .223 in my opinion) without stretching things too much foxes 250 yds to be realistic,although Im sure they have been taken further, Roe, Muntjac, cwd, I would keep to 200 as an absolute max for deer,preferebly 150 yds, but with good shot placement a.222 is a very good small deer calibre, and really shines when reloaded, Sierra make a superb 55gn prohunter which would be my first choice if rolling your own, you will probably struggle to find factory ammo that has a deer bullet as apposed to a varmint bullet,that said Hornady v