NC doesn't mention any minimum caliber in our regs for deer...
As far as the .243, I've killed about 150 with it through the years, course I used "Premium" bullets for abut 80 of them...
As long as you consider CoreLokts 'Premium"....
Never thought of the .243 as too small, until I got "educated" in the internet...As to the advantages to shooting a mild kicker....
I shoot year round, not just targets, but also crows, groundhogs, coyotes etc....If I can hit a crow at 300 yards in August, I know
I can hit a deer in the lungs at 300 in October....I never lose sight of the deer after the shot...I can switch shoulders and shoot off my left
shoulder and don't have to worry about the scope "biting" me....I don't flinch, guys shooting larger calibers actually bring them to me
to sight in....I can drop a deer on the spot by putting a bullet through the shoulder blades, by shooting them through the lungs they drop within 40-70 yards, about the same as my brother's .270..
It's amazing that the 250 Savage and 257 Roberts were considered fine deer cartridges in the 50's when the .243 was introduced,
but the .243 is considered "too small"....And the .243 out sells both of those fine older cartridges by a wide margin....