I'll look it up when I get home. I believe there is a clause in fed law that you still need to abide by your local laws.
You are correct. There is a section, I believe it's somewhere in 922, that specifies that all firearms sales have to comply with the laws of the purchaser's state of residence. It's the same reason that an Illinois or Jersey resident, for example, can't go to a free state and buy a long gun without an FOID card.