I own a few handguns, I asked another question to the LEO's here in Livonia and of course they do not know. I also asked MSP, and they wouldn't give me and answer.
The Clinton Gun Ban is dead.
My XD-40 can carry double stacked 10+ round mag's.
If for what ever reason I am asked to show the permit and I have more than the "10 rnds" as per what is on the permit, will I face legal trouble?
No one knew....
I know Beta C's are legal, but this is a handgun and there is no ppwk with those (beta's) that states what/ and how many...
Can't cite any particular law but I wouldn't sweat it.
I shoot in competitions with guys who use oversize mags (up to 21 rounds) in 7/8/10 shot handguns all the time. We've yet to attract the attention of the gendarmes. Several of the guys I shoot with are local cops / MSP. I use +2 and +4 extensions on my Glock mags. No one has said anything.
I don't know why the green card has the '## Shots' entry. No one seems to use it for anything. It might be there to help identify the weapon in case of destroyed serial number, etc but it isn't used as a magazine capacity limit.
Michigan has no restrictions on handgun magazine capacity (unless you're hunting birds). The green card isn't a permit anyway, it's a registration disguised as a certificate of "safety inspection". There is no legal requirement to carry your "green card" with your pistol, and I frequently don't. Your Michigan CPL certainly doesn't restrict you to a magazine capacity. Don't sweat it.
It doesn't surprise me that the MI State Police won't tell you; they probably don't know. I know that they don't understand federal regulations governing interstate pistol sales.