15 victims from a 15 round magazine is asking for some good marksmanship
Literal much? smirk

Think concept, man. Potential. Opportunity. Sure, every cast member of Walking Dead can make every round a head shot from a quarter mile away. crazy I'm talking about suppressing the opportunity to inflict harm on a grand scale.

And as for your first point, if you consider that among all of those single victim incidents, without a gun, many of those would be injuries vs. deaths. And further, many of those assailants preferred the convenience and hand's off function of a gun over getting up close and personal with their victims. If this were true in only 10% of those cases, those are lives saved.

I've heard stories of 90 shots fired with less than 10% hitting the target in some cases.
This is the best ever argument for NOT having guns in schools in the hands of trained pros, or especially teachers and staff!