[perfect stranger]

With knowledge of guns and machine tools it's not very dificult to build a gun. It's a strange design. It doesn't look balanced. How can you get any accuracy with it?

[Sacajaweau]

No one says it really shoots (or have they). I'd label him "the junkyard killer".

I wonder if there is a dump nearby although every machine shop is its' own dump.

[ExSoldier]

"How can you get any accuracy with it?"

Good point. Methinks you'd have to be very close which begs the question: If you're going to work at knife range, why even use a gun? I realize that a projectile will possibly produce more "shock power" than a nice sharp blade, but correctly executed, a knife thrust will do the job just fine.