That's not exactly how it works. The "safety inspection" process doesn't take much time at all, especailly if you are moving into the state and the pistols are already in your possesion.
If you move into the state, you take your pistols to the local P.D. (or Sheriff if there is no local P.D.) You explain that you moved into the state and need to have the pistols you purchased out-of-state before you became a Michigan resident "Safety Inspected."
The police have you fill out a "Permit to purchase" for the pistol. My understanding is you would list yourself as both the seller and the buyer (the form is normally used when you buy a pistol in the state).
The police will then "Safety Inspect" the pistol. They'll record the serial number, run a LIEN check (usually, if not always) and fill out your "Michigan Pistol Safety Inspection" card. The "Safety Inspection" card is three parts. One is retained by the local P.D., the second is sent to the Michigan State Police and the third is given to the owner of the firearm as proof that the "Safety Inspection" was completed. Even though it is called a "Safety Inspection," it is a registration and many police departments do call it that.
There is nothing inherent in the process that would make it take more than one day when you are brining in pistols from out-of-state as a new Michigan resident. You could get your "purchase permit" and have the "Safety inspection" done on the same visit.
Normally, if you were buying a gun as a Michigan resident, you'd have to get the "Purchase permit" before you pick the gun up from the gun shop and then you'd have to return to the P.D. for the "safety inspection. This means you have to make multiple trips to the P.D. The "Purchase Permit" is valid for 10 days after issue to allow for this. Obviously, this isn't the case when you already have the gun in your possession because you brought it with you from out of state.
The only things I can think of that might add time to the process is if the local P.D. restricts the hours that they will issue purchase permits or perform safety inspections. The P.D.'s are supposed to offer this service during normal business hours, but some P.D.'s do set limited days or hours for this. The "purchase permit" is also required to be notarized and, if the P.D. does not have a notary, I can see where this would add some time because you'd have to pick up the permits, find a notary to get it notarized, and then return. Most P.D.s will notarize the permits though.
I also believe that state law says you have 30 days to have pistols "safety inspected" when you move into the state. I could be wrong on this though, as I don't have the law in front of me.
