The only problem is that if you let them ban 100 round mags then they'll be after 50 round mags next. So, you say, well you don't need 50 to hunt with, ban em'. So they do and then they'll want 30 round mags and on and on it goes until all mags are banned and you're feeding you're semi one round at a time.
Screw em', I don't want ANY mags banned and I don't care if they're acceptable for hunting or not, that's NOT what the 2nd Amendment is about anyway. Any gun owner that'd cave in to a little anti-gun laws should just sell their damn guns because they're not standing up for the 2A and don't deserve to own firearms in the first place.