first, define an 'assault rifle"... then watch me demonstrate how something that doesn't match your definition of 'assault rifle' is functionally identical to another weapon you did designate as one.
next, Posit proof that enacting law that affects millions of people, to possibly extend the lives of a handful of people in extremely rare events, until they die from one of the 1000 other more life-threatening events we face every day. Extra Credit for postulating how this is "Responsible Civic Action".
Wait a second, you said Right to Carry, not "own", alright then, well, millions of us already have the legal right to carry a pistol (and the paperwork that goes with it), but we can't carry around semiautomatic magazine-fed rifles (*) legally in a lot of states. Cool, you got your wish, it's already reality.
(* - I believe this is the phrase you're looking for, "assault rifle" is a term from video games that isn't used by anyone with any weapons handling experience in the real world)