It's not the cartridge, it's the person pulling the trigger! Personally, I believe the .243 is a great beginner's choice with limited range based on a new hunter's skills. I've had to track a lot of deer that were shot with a .243; but I attribute that to the shooter and not the choice of caliber. For me, I don't have the confidence in a .223 or .243 for me to consistently make killing shots with those cartridges on deer. On the other hand, I know people who kill deer with .22 magnums, .17 hmr, and plenty who use a .22-250 and always drop their deer in it's tracks. I'm not that good, and my eyesight absolutely isn't. That's why I use a .308 or a .270 for the majority of my rifle hunting, and a 12 gauge loaded with either #1 or 00 buckshot when hunting with dogs.
If you have the skill and can make the shot consistently, then by all means don't hesitate to use whatever cartridge you feel comfortable with. After all, shot placement is what kills deer, not the size of the bullet!
NRA LM, NAHC LM, Buckmasters LM, The Second Amendment Foundation, GOA, NAGR, Palmetto Gun Rights, QDMA, DU, NWTF, ASAdisabled sportsmens' alliance, EDH, and Proud SC redneck REBEL for life.