[Pis-ton broke]

Jay Leno uses a three d printer to make unavalible car parts.
So this guy made a gun, I see a part off a gun. but its doable to turn up (at machine shop) a steel barrel and a tool steel firing pin. from an engineering point of veiw its clever IMO.

but on the other hand it might be a can of worms, a full plastic gun needs to fire only once to cause a disater. As plastic gun may not be picked up on a body scanner etc. I don,t know , maybe it will.