MICHIGAN;
Purchasing and Registering a Pistol in Michigan
In Michigan, a person "shall not purchase, carry, or transport a pistol in this state without first having obtained a license for the pistol," as prescribed in MCL 28.422. These licenses shall be obtained by the local police agency. If the city, township, or village does not have an organized police agency, the license shall be obtained by the county sheriff department.
There is an exception for a person licensed in Michigan to carry a concealed pistol. He or she must obtain a Pistol Sales Record (RI-060) any time he or she purchases or otherwise acquires a pistol, pursuant to MCL 28.422a.
The police authority will check for any criminal record at both the state and national level.
MSP - Purchasing and Registering a Pistol in Michigan
So, basically
When buying from a GS or Show, you will have the NICS and 4473 filled out, no matter what(handgun/longun) , even if you are a CPL holder, but for a handgun you must have a license to purchase form from the local police with you, CPL holders will have an RI-60 filled out on them.
If you purchase a handgun from a private seller, AND DO NOT have a CPL, you must go to police or sheriff office, fill out 10 question safety test,they do a NICS, you get your license to purchase permit, then you have 10 days to buy it and return the local and MSP copies back to them{you keep one as well as the seller}.
If you have a CPL you can buy from a private seller, just having the seller fill out what is called an RI-60 form, and then the buyer turns in the two copies to the local police, who in turn send one to the MSP.
Long guns there is nothing to wait on or permit/form to fill out when buying from a private seller.
Seems confusing, but its no where near as hard as Cali or NY or MA or the like.