This too. The cheapest full auto is a worn out MAC10 that still goes for $3K+. In addition you need to go through a lot of paperwork, fingerprints, FBI background check, and it takes at least 6 months. Most or all of your full auto owners are collectors.
Even if the Federal Assault Weapons ban is reinstated, what will that solve? Columbine happened in 1999. The ban was from 1994 to 2004. Looks like that worked well.