The Second Amendment gives no one the right to open fire indiscriminately. There are limitations without encroaching on the basic right. Your rights cannot violate my rights. A right, by definition, is for the common welfare of people. With rights comes enormous responsibility to exercise those right in a thoughtful, conscientious manner.
Rights are subject to revocation.
There is no waiting period on the freedom of speech, nor is it subject to licensing or registration. Many of the firearms laws on the books are, indeed, unconstitutional.