I'm not a lawyer, have never played one (preferring to play Doctor), and didn't even stay in a Holiday Inn Express last night, so I went to the source - North Dakota state law. The applicable section is Section 62.1 of the ND Century Code. Here's what it says for all sorts of things states might wanna ban:
62.1-05-01. Possession and sale of machine guns, automatic rifles, silencers, and bombs - Penalty - Forfeiture. No person may purchase, sell, have, or possess a machine gun, fully automatic rifle, silencer, or bomb loaded with explosives or poisonous or dangerous gases, or any other federally licensed firearm or dangerous weapon unless that person has complied with the National Firearms Act [26 U.S.C. 5801-5872].
Short, simple, and the state does not add anything to Federal rules. While you're at it, try throwing this in as well.
62.1-01-03. Limitation on authority of political subdivision regarding firearms. No political subdivision, including home rule cities or counties, may enact any ordinance relating to the purchase, sale, ownership, transfer of ownership, registration, or licensure of firearms and ammunition which is more restrictive than state law. All such existing ordinances are void.
Good luck.