The number of deadly incidents is only one factor that should be taken into consideration when dealing with deadly devices, guns, bombs or whatever.
If you knew some crazy kid was hell bent on shooting up a school and you had the power to limit the type of weapon he could use as, say, between a single action pistol and a bump stocked AR-15, we know which one you would choose without any hesitation about the Second Amendment. Liberty has its limits.
In fact liberty is probably the most abused word in these United States. The human ego is infuriated anytime someone tells it no.
We have thousands of laws, rules and restrictions so that one man’s liberty doesn’t trample another’s. The best rules are based on pure practicality not freedom. If an AR-15 serves no practical good, yet has the power to permanently end anther’s man’s liberty, it needs to go. That’s called common sense.