Didn't the Kennedy sniper fire 3 rounds from a bolt gun in 2 seconds? isn't that the capacity to kill a lot of people in a short amount of time? Besides, that argument is ridiculous. Would he prefer that people are killed slowly? Look at the DC sniper, they had a Bushmaster. Did they kill more than one person at a time? no. Three on one day IIRC but you could do that with a muzzleloader.
I would bet that the number of people killed in/by Honda Civics exceeds the number of people killed by assault weapons. Should we ban Honda Civics because of this? Should we ban high-performance cars like the Corvette, Viper, or Mustang? Because who needs a Corvette, really? There's no reason at all, other than to have fun with, or show off.
I read a paper by the VPC saying that "sniper weapons" were very different from hunting weapons, and they defined a hunting weapon as a .30-30 used no farther than 200 yards. Therefore, as they presented it, any weapon with the capacity to kill beyond 200 yards was a sniper weapon. In reality, they took one of the weakest rounds used by hunters, and definitely the weakest .30 cal round, and made it out to be what all hunters use, and that there was no reason to have anything more powerful.
The car analogy to that is that a 3 liter V6 making 170hp is the most anyone would ever need to get around, and that anything with more than 3 liters or 170hp or that does 0-60 in under 9 seconds should be illegal.