Nathaniel, You can have an AR pistol in MI. It has to be on a virgin pistol lower and be shorter then 26" fully extended. The OAL applies to long guns (rifles and shotguns) in both federal and Michigan law. To be legal, the Ar15 pistol must be built on a virgin lower receiver, one that has never been part of a rifle. If it was part of a rifle, then it becomes a short barrel rifle. The AR pistol must have OAL of 26" or less.

Source?
What ive read is
The following are prohibited:
Pistols with an overall length greater than 26”
o For example, check the overall length of AR / AK pistols to be certain of compliance
An AR with a 10½" barrel meadures Overall Length25.30" - 27.90"
So if you got one a little shorter that should be compliant
budsgunshop.com/feeds/state_reg/michigan_restrictions.pdf />Uscca is insurance for conceale carry a
They stay pretty up to date on state gun laws and it says you CAN build an ar pistol if the overall lenght is under 26"
usconcealedcarry.com/blog/keeping-your-ar-15-pistol-build-within-legal-limits/

Nathaniel, you are very welcome Sir. Cheers and stay safe!