I seen a video, a good while ago now of a guy on here who made an EMP gun. He tested it out of a cell phone from a reasonable distance away, and it fried it. I obviously can't vouch for it's authentic...
A cell phone wouldn’t have any shielding as that would increase the weight unnecessarily, but I’m not saying it’s impossible just impractical. A regular gun would do more damage from a much greater distance and with greater precision.