It appears that they may not necessarily have a preemption clause. I was planning to OC on Ocracoke for a benefit concert/mini-festival in a few weeks and ran across this section of state code:
§ 14‑277.2. Weapons at parades, etc., prohibited.
http://www.ncga.state.nc.us/EnactedLegislation/Statutes/HTML/BySection/Chapter_14/GS_14-277.2.html
Except upon second read it appears to apply only to state or local "public" property and this event will be held on private property.
It seems that NC has a simpler code section regarding firearms that VA, but cannot immediately locate a "preemption" type section.
Also, CC permits carry.
http://www.ncga.state.nc.us/EnactedLegislation/Statutes/HTML/BySection/Chapter_14/GS_14-269.html
http://www.ncga.state.nc.us/EnactedLegislation/Statutes/HTML/BySection/Chapter_14/GS_14-269.3.html
§ 14‑269.3. Carrying weapons into assemblies and establishments where alcoholic beverages are sold and consumed. (a) It shall be unlawful for any person to carry any gun, rifle, or pistol into any assembly where a fee has been charged for admission thereto, or into any establishment in which alcoholic beverages are sold and consumed. Any person violating the provisions of this section shall be guilty of a Class 1 misdemeanor.
(b) This section shall not apply to the following:
(1) A person exempted from the provisions of G.S. 14‑269;
(2) The owner or lessee of the premises or business establishment;
(3) A person participating in the event, if he is carrying a gun, rifle, or pistol with the permission of the owner, lessee, or person or organization sponsoring the event; and
(4) A person registered or hired as a security guard by the owner, lessee, or person or organization sponsoring the event. (1977, c. 1016, s. 1; 1981, c. 412, s. 4, c. 747, s. 66; 1993, c. 539, s. 165; 1994, Ex. Sess., c. 24, s. 14(c).)