Re: Guns...
In answer to your question, yes, it's already been done. One is in production and marketed to law enforcement for exactly this purpose.
New rifle shoots drones out of the sky without firing a single bullet ...
http://bgr.com/2015/10/16/drone-defender-rifle-radio-wave-gun/
Oct 16, 2015 ... One would need to be quite the marksman to shoot a drone out of the sky with a ... a device it calls the DroneDefender, which it says is “the first portable, ... Beyond that, military, governments and law enforcement are targeted by spy drones on .... Which would then be followed by the handheld EMP cannon.