Title 49 CFR states in Chapter 1, section 173.63 the packaging exceptions to full regulation. Under that section, (b) Cartridges, small arms, may be reclassed, and offered for transportation, and transported as ORM–D material when packaged in accordance with paragraph (b)(2) of this section; such transportation is excepted from the requirements of subparts E (Labeling) of part 172 of this subchapter. Cartridges, small arms, and cartridges power devices that may be shipped as ORM–D material is limited to:
Under this “limited to” section, there is item (i) Ammunition for rifle, pistol or shotgun; and (iv) Ammunition not exceeding 12.7 mm (50 caliber or 0.5 inch) for rifle or pistol, cartridges or 8 gauge for shot shells.
This is the critical part to shipping ammunition. If it is 50 caliber or less, or 8 gauge or less, UPS will take the shipment in a sturdy box marked with a ORM-D, Cartridges, Small Arms label on the outside of the box. UPS does recommend using this label as opposed to a regular ORM-D label from our research and inquiries to UPS themselves. Part 172, subchapter E states the label should be affixed near the shipping address location on the package. By placing it here, the carrier will see it as they direct the package to the correct location during shipment.
Now, under section 173.115, part (v) it states that cartridges, and 22 caliber rim-fire cartridges may be packaged loose in strong outside packaging. The label marking is the same as above.
You are fine as long as it is marked appropriately, and you are the correct age to accept the ammunition. There should be no North Carolina law limiting the shipment of ammo, to my knowledge... however if he is sending you pistol ammuntion you must be 21 but I assume you are.