This is how Class 2 firearms goes in Michigan:
Michigan Law states you have to be licensed to own a class 2 weapon. (Commonly called class III, but dealers are Class III and the weapons are class II)
Michigan Law is void of any procedure to obtain a license to own these guns. So private ownership of class II weapons was summarily considered invalid in Michigan.
However, CLASS III DEALERS license holders by DEFINITION have a LICENSE granted by the ATF and are allowed to own class II weapons.
So, the bottom line is that a private citizen could not own class II weapons, but a class III dealer can.
In 2005, the Attorney General wrote an opinion that made private ownership of MACHINE GUNS legal in Michigan. Opinion Letter LINK HERE.
Essentially saying that the NFA Tax Stamp fulfills the requirement for "license" as described in the Michigan Law for MACHINE GUNS.
Atty General Mike Cox in 2005 nullified a 1980's era opinion letter and now PRIVATE MACHINE GUN ownership is LEGAL in MICHIGAN.
However, the controversy is weather this opinion applies to all class II items or just to MACHINE GUNS ONLY. Right now, the letter of the law implies MACHINE GUNS ONLY.
However, if the NFA Stamp is a de-facto license, then it *should* apply to all NFA items.
Since Atty General Cox's bid for the Governors race ended with him NOT receiving nomination for his party, speculation has it that he may be waiting for the end of the Nov 2 election before he drafts another letter addressing suppressors and maybe sbrs and aows.