Persons who are twenty-one years of age or older can purchase a firearm from a federally licensed dealer licensed to sell within the state.  A person may temporarily borrow or rent a firearm for lawful sporting purposes throughout the United States, provided that all other laws are complied with.  A person is allowed to transport a firearm across state lines from one place where it is legal to possess firearms to another place where it is legal to possess firearms.  Some states prohibit the carrying of uncased long guns in the passenger compartment of a vehicle after dark.  Federal law prohibits the carrying of any firearm, concealed or unconcealed, on or about the person or in carry-on baggage while aboard an aircraft.