You can kill a fly with a teaspoon or with a fry-pan. But a fly swatter works a lot better. I don't know much about the deer or the hunting conditions in Florida. If you are willing and able to only take standing broadside shots at undesturbed deer at less than 100 yds. Or if you are hunting with hounds(that will find your shot deer) and you have a semi auto and shots are at running deer at 50 yds. and less. Maybe the 223 will do. I would tend to say it is not the best deer round.
I live in Alberta where bucks can be really big and not all that plentiful. Sometimes a monster steps out on a powerline 300 yds. away and you have to take a shot as he walks away from you or not see him again. Then I want a good heavy slug traveling at warp speed in an accurate rifle. I shoot 140 grin bullets from a .264 win. mag. in a win. model 70 bolt gun.

Robin