we've killed a couple with the .223, but several with the .357.
others may swear by the .223, but I'm not that impressed. we used good bullets and hit the deer perfectly (broadside, armpit) with a 65gr softpoint. it worked, but not near as well as our 185 gr hardcast leads from the .357.
given my druthers, I'd pick the .357 every time and not look back. it works great and recoil is pretty mild in our heavier (octagon) barrelled lever gun.