The only thing I'd take away from this movie is that the lobbies have a lot of power to try and manipulate politics.
However, the movie doesn't answer or properly deal with the problems that the law they're pushing will cause. Or the fact that the law is useless and does not stop people from acquiring firearms.
There also was a scene where it essentially gave away the ending. It isn't subtle or anything, but it essentially guaranteed how the movie would end. Which felt cheap, and tried to justify the martyrdom that the ending had.