The biggest hurdle is, of course, arriving at a definition all can agree on. Some gun advocates will argue that those without a working knowledge of the minutiae of firearms should have no voice due to their lack of expertise. This, of course, is as silly as saying if you don't know what type of tacks an upholsterer used, you should not comment on the comfort of an armchair. Or if you don't know the proper timing sequence of a 351 Cleveland V-8, you have no voice in a discussion of automobile safety.
To me the definition should coalesce around three factors:
The rate of fire. This is what puts the 'mass' in 'mass shooting'. No one is capable of murdering so many people in a short time with a knife or club, or bolt action rifle.
The muzzle velocity. A round fired from some weapons is substantially slower and delivers less impact measured in foot pounds per second than other weapons. The lethality of such rounds is exponentially greater than others.
And finally, practicality beyond sporting weapons. Some guns are designed to hunt quail or pheasant or turkey. Some are designed to hunt deer or moose or mountain goat. Some weapons are designed for target shooting. Punching holes in paper or shattering clay pigeons. But some weapons are designed to kill as many people as possible as quickly as possible.
And, for heaven's sake, let us not get bogged down with cosmetics. Grips, stocks and flash suppressors do not impact the design purpose of assault weapons.
Rate of fire and muzzle velocity won't get you there either.
Because semiautomatic pistols have the same rate of fire as semiautomatic rifles...it's no stretch to argue that one ban leads right into the next...banning semiautomatic pistols...as they also have minimal sporting purpose and are mostly used for self defense.
Attempting to link any ban to sporting purpose will be almost certainly be overturned by the High Court, as firearms for defensive purposes are specificly protected by Miller.
What type of weaponry is envisioned to be used by school staff as defensive weapons? Surely the same type of weapon called upon to defend a classroom is adequate for defense of a home. So how can linking some semi-automatic weapons to a self defense role be made?
If weapons have minimal usage as sporting weapons, but fine for self defense, what special virtues do these weapons uniquely hold?
Likely 80% of defensive firearms owned in the U.S. are semiautomatic weapons.
Your statement implies eventual confiscation. A ban on further sale, trade, importation, manufacture and distribution simply stops the flow of such weapons.
Remember, no law I said a panacea. Speed limit laws have not eliminated speeding. Laws prohibiting fraud or perjury have not, God knows, stopped tho 9se crimes. But laws have been proven to slow the incidence of crime.
How many mass shootings have there been using semiautomatic rifles?...four?...five? Newtown, Aurora, Las Vegas, this one, and I think I'm missing one.
There are approximately six million AR15 type firearms legally owned in the U.S.
Those six or ten or twenty individuals who want to kill people...they are going to find a way, just like those terrorists who used the truck as a weapon, or the gas attack on the subway or the Columbine shooters who had propane tank bombs.
Just take a look on the internet:
Hell...give me a 10 lbs bag of flour and 10 minutes, and I can demolish your house.
Point being...banning a weapon that 99.99992% of legal owner are using legally and responsibly is not only not a pancea... will solve nothing. The next mass killer will just use something else.
