OK folks, here is the thing about 'bump stocks'. They are a gimmick. They are an expensive piece of plastic that allows you to do something with some types of rifles that you can technically do with a rubber band or even just proper training on a different way to hold your rifle.
A bump stock basically works like this. In a normal semi-automatic rifle, every time you pull the trigger with your finger it fires. A bump stock holds your finger still on the trigger and moves the gun back and forth with each shot recoil, so your finger is steady and the gun is moving (exact opposite of how you are taught to shoot).
You can do the exact same thing with a rubber band threaded around your finger and the trigger and across the magazine (I've also seen it through the belt loop). Like this:
You can even train yourself to hold the rifle in a certain way to 'bump' fire without the rubber band. (kind of complicated but basically you do not hold the rifle at all with your trigger hand, you just keep it there in one spot and support the rifle by the barrel only- don't try this at home kids)....
All a Bump Stock does 99.999999% of the time is separate a sucker from their money.
And to add one more piece of complexity to this- you can 3D print a bump fire stock with plans all over the internet for about $10 worth of plastic thread.
Banning these are literally a useless piece of symbolism.
