I write a bill of sale between me and the individual here in Alabama. Never sold a gun before expect to my father in law or a close friend.Here in the state of Illinois we have had the FOID card since 1968. We have to have the card to buy firearms and ammo. If selling to another person we have to call in their FOID number and get a confirmation from ISP that the card is OK.
Having said that , I am wondering what one has to do to sell a firearm to another in your state without going through an FFL.