Heh, you'll love this one...
Here is the most recent explanation by a local LEO I was given on this one:
First, understand that they are for sale in every single gun shop in the state. It is perfectly legal for the dealer to sell them to you. It is perfectly legal for you to buy them. However, according the way the laws can be interpreted, it is illegal for you to carry them out the door. BUT, it is perfectly legal for you to possess them in your home. It is also technically illegal to fire them at the range or anywhere for that matter.
Now, this is one of those things that is simply not enforced. It might even prove to be "unenforcable" should it ever actually be tested in court. I don't know and am certainly not willing to volunteer to be the test case... Also, we all know that local LEO interpretation of law varies WILDLY from LEO to LEO. But, I have been given this same explanation several times.
Everybody here owns them and everybody here shoots them.