Or if he could somehow rifle the projectiles. He might be capable of doing this by simply making a spiral pattern across each one with a paint or tape that offers some sort of electrical resistance. This would at least make it so the projectiles don't flail through the air and perhaps are more consistent at making some penetration like the one that went through the laptop.
This is an irritant not a weapon. I think he'd have been better off with one short but super strong coil. He complicated it with switches and several tiny coils that don't make any sense. His idea, clean parts and design is pretty much flawless other than that though, so kudos. But seriously, a disassembled electric staple gun can do more damage than this for .
Oh, I don't know, it's nice to see everyone can be so blasé about honest-to-fuck mad science these days. Used to be a time when you couldn't build a walking automatic jar opener out of dead criminals without the whole neighborhood flipping its collective wig and burning your house down.