Banning bump stocks after Vegas would have been "doing something." It's not nothing, but it would have had no effect on most other mass shootings in US history including the one last week. Likewise, instituting psych evaluation rules for gun purchases would be "doing something" in response to Florida but would have had no impact on the Vegas shooting and several others. I'm in favor of both of those changes, but my goal would be to make any policy have broad enough reach as to make it much harder for any person to commit mass murder using a gun.

With that in mind, my first policy prescription would be to ban the manufacture and sale of semiautomatic rifles (AR-15 etc) and large magazine handguns (say >10 rounds). I know of no practical civilian use for either of those guns in defense or hunting. They are "gee whiz that's cool" toys for use on a gun range (and I've fired both). I have read arguments why AR-15's are "needed" because they are the most convenient guns to modify and tinker with inexpensively. That line of reasoning is both a feature and a bug of the gun. It is also not an argument for need, but rather for economy of time and cost. I don't interpret the 2nd amendment to mean that you have a right to a convenient inexpensive gun.

A bolt action rifle is perfectly adequate for hunting. A revolver or 10 round semi-auto handgun is plenty for concealed carry. A shotgun with a 3 round magazine is good for hunting, recreation, and home defense. We have always held that certain guns and weapons can be regulated (Joe 6-pack isn't allowed to own a tank or a nuke). There is no reason that the types of guns that are most convenient for use in mass shootings could not be similarly regulated. Such a change would not prevent all possible shootings, but it would make it harder to kill large numbers of people in a very short time.