You can thank the Federal Government for such nonsense.
The Pistol Purchase Permit is NC's answer to the mandatory background check requirements from the Brady Handgun Act (and changed by the implementation of NICS).
You go to the local Sheriff's office, get the background check done, and they give you between 1 and 5 Pistol Purchase Permits. Five bucks each.
You then have a number of days (30? 60?
) to use the permits to buy pistols before they expire.
He'll have to show his orders to Bragg to prove that he's a resident (albeit temporarily) of NC, otherwise he can run afoul of the Federal Firearms laws restricting out of state handgun purchases.
If he gets a NC concealed carry permit (which is where the training course comes in), then the state recognizes the background check done for that as sufficient for purchasing handguns for as long as the permit is valid - typically five years. Concealed Permits are more expensive - you'll likely spend 75-100 bucks for the training and another 50-60 bucks for the permit application. They take longer, too - six weeks or so for the full background check. The upside is that you can carry a concealed weapon, you can have a loaded weapon in your car without it being in plain sight, and you can go buy any handgun you want, any time you want, without having to first get a purchase permit.
The Concealed Carry classes aren't a complete waste of time. You spend quite a bit of time going over NC laws regarding self-defense, i.e. under what circumstances you're legally able to USE a firearm. Also covered is what you're required to do if approached by a law enforcement official while carrying a firearm. You also go over stuff about where you can and can't legally carry a firearm, including places where you can carry a firearm, but not concealed, and some other places where you might be able to carry a firearm, but not openly. If you're going to actually USE a concealed carry permit, you need to know that stuff, no matter how safe you are around firearms or how well you know how to use them. And honestly, are there any of us who couldn't use a refresher on firearms safety every now and then?