Since it looks like the ban is going to pass (I'm still holding out hope but not much) I'm wondering how that's going to impact currently owned mags. Since you will not be able to transfer them it seems that they will need to be destroyed or turned in if something happens to you.
So your family can have your rifles but not the mags if nothing is done to insure they can take possession.
I'm not a lawyer but this is how it looks to me.