I have checked this out before. OC is legal in NC but full of caveats and is very risky. Statutes do not forbid OC, but NC has a statute about "going armed to the terror of the people". That is so vague that it can be used in nearly any situation. Example: Walk down the street doing OC, minding your own business, bothering no one. No one complains, all is well. A bedwetter happens by and sees your weapon, screams out "he's got a gun!" and starts a panic. Guess who gets arrested and charged? That 1 person's overreaction defines you as "armed to the terror of the people". At the least, if you OC, prepare to be stopped & questioned in most areas.
The few times I have seen OC in NC were isolated circumstances. I used to see a few people OC while fishing at a lake or river, probably loaded with snake shot. I have seen a few store owners or gas station clerks OC every now and then. A store owner in Durham always has his .357 on his hip. A person on his own premises is much less likely to be bothered, as others can use his services or not, their choice. I saw one guy in a book store, carrying on his hip & not wearing any uniform, badge or police T shirt. He looked like he could easily be police or military but not identified.
I only OC'd one time. I worked a job in a BAD neighborhood after a major theft at the property. I was alone much of the time & this was a place where people come up to bum money frequently. I had property owner's permission & stayed on the property, barely ventured on the street at all. I carried crossdraw, where it was not obvious to casual passersby but obvious to someone approaching me. A neighbor there came over to ask about work & was not disturbed at sight of my weapon.