***they are “designed to kill large numbers of people quickly.” ***
Bunkum. Charles Whitman used a bolt action to kill most of the sixteen people in 1966.
Richard Speck did not use any guns to kill six student nurses in the same year.
Mark Essex used a Ruger Deerslayer 5 shot tube fed .44 magnum to kill nine people in New Orleans in 1973.
Ronald Gene Simmons strangled seven of his 16 victims, drowned one and shot the other half with a single action Ruger.22 pistol.
This is just another attempt to ban guns by any means. Throw a gun law against the wall and see if it sticks, then build on it to confiscate the rest.
Why doesn't somebody design a hammer to "hit large numbers of nails quickly"? The entire world would benefit, and make the inventor richer than Soros.