Here in Michigan the state has records of ownership on handguns as you have to have a purchase permit and had to take them to police station or sheriff office with 10 days or purchase. Now it you have a Concealed Pistol License you can just fill out a three part form, the seller get one, you get the other and the other has to mailed to the police department or sheriff department to be entered into the Michigan State Police data bank. Police were originally exempt from this but now they are not. Long guns the only records are Federal Firearms Dealers form if purchase there. Supposedly the Feds don't keep records of them after 30 days but I would not bet on it. No records of sales of long guns between private individuals, Yet!