You cannot bring any 30 round mag into CT as of this afternoon. None. It doesn't matter why you want to, you can't.
Any mags you have here can be registered, though no one knows how that works yet, because the ****ing a**h***s running this clown show didn't specify in the law they just passed how to do it.
Violating the law more than once makes you a felon. No word on if "more than once" means on more than one occasion, or just more than one mag on a single occasion.
If you register and own 30rd "CT 2013 PreAWB" mags you cannot load more than 10 rounds into them other than when at home TARGET SHOOTING or at the range TARGET SHOOTING. You may carry normal capacity mags, but not load more than 10 rounds in them even for self defense at home.
It's all for the dead children at Sandy Hook you gun toting baby killer.