I do not have the answer but something needs to change. You are completely wrong saying that a guy with a single shot and buckshot can cause the same damage as with an AR. No way the Vegas killer was going to that with a shotgun. I will say if the AR went away I would not miss it. The rapid fire rifle I own is a 98 mauser and it has all the firepower I require.
I know you don't have an answer with a law...because there is no law that would've made a bit of difference.
Truth is if the AR was banned you're Mauser a weapon of destructive force a lot greater than a little AR could be next...
No one mentioned the Las Vegas shooter.
But since you mentioned him....
Would it really have made a difference if he had a bolt action rifle with a high powdered scope and just selectively popped peoples heads off ?
You think either is more or less evil...
Is just one life not worth as much as many ?