Can we agree that weapons with 30 - 100 round magazines...extended barrels, and 3,200+ fpm velocities can be much more lethal when used against human beings than weapons with 10 or less rounds and velocities below 1,200 fps? Note the links i've provided from experts in the field of armaments...and medicine...that support this contention.
Note also that as you've already shown, there are scads of guns to choose from...yet, all of the grotesque killings we're seeing are perpetrated with one class...i.e. Assault Rifles (e.g. AR-15)...why do you suppose this is?...
Finally, I'll reiterate that both Australia and New Zealand have banned such weapons with the result that since they did that, only one mass shooting has occurred...all those other firearms that don't fit the category are still available, but surprisingly they aren't being used!...imagine that.
So, we have solid evidence that banning such weapons will indeed reduce or even eliminate events that none of us want...without harming any Hunters, Marksmen, or Home Defenders...Woo-Hoo!...problem solved...all it takes is some political courage by our national leaders.