The firearm fired most at Columbine was FULLY COMPLIANT with the 1994 Assault Weapons Ban.
The firearms that would be covered (most likely) in the soon to be proposed Assault Weapons Ban by D. Feinstein (look for it on Thursday, this week) are responsible for an insignificant (statistically speaking) amount of all firearms deaths in this country.
MADD was successful by going after the perpetrator... not the objects used. Cars have not been banned. Alcohol has not been banned. In fact, in most of this country you can use your vehicle for manslaughter while you are drunk... and get your license to drive back after your prison term, which is, in many cases, less than 10 years. And you can do it all over again.
The shootings in Sandy Hook and Aurora, and Columbine and most everywhere else for that matter, were perpetrated by madmen.
On the same day as Sandy Hook, a madman in China attempted to kill 22 students and an elderly woman with knives and an axe.
There are nearly as many incidents of armed school administrators and students actually stopping mass murders as there are successful mass murders.
I think your efforts would be better spent, just as they were with MADD, by enforcing stiffer penalties on those who commit crime with firearms, rather than focusing on the inanimate objects that in and of themselves do no harm.
I have available citations for all the facts I have presented... Though I have been led to believe that those who wish to ban guns have no interest in facts... they just want to feel like they're doing something... If you care to prove me wrong, reply to my statements asking for the citations.