I've always been told that the .223 Rem. round wasn't good for deer hunting ,,,,,,,,,,?

People kill deer with 223's, but that doesn't make it a good idea. Neither are deer killed with foot-pounds. I killed close to a hundred small southern deer with a 6mm in my youth and finally decided it wasn't enough gun, either. It'll do, but there's no prize for using a marginal caliber when it's so easy to pick one that's adequate for almost any shot you'd want to take. Pick something from 6.5 Swedish Mauser/260 Remington on up, and you won't have to worry every time you shoot whether the bullet will do its job.