mandrel

In 2012, for example, police in Virginia took $17,550 from Mandrel Stuart, a Black restaurant owner pulled over for a traffic violation.

And he designed a homemade barrel by carving spiral grooves—the rifling that makes the bullet spin—inside a metal tube using electrochemical machining, which may sound complicated, but it’s a relatively simple DIY solution to etch steel using saltwater, electricity, and copper wire twisted around a 3D-printed mandrel.

The result has been stories such as that of Mandrel Stuart, a barbecue restaurant owner from whom Fairfax County police took $17,550 in 2012.

Mandrel Stuart was pulled over because the SUV he was driving had tinted windows and a video playing in his line of sight.

A central metal stick, called a mandrel, is mechanically pulled out of the rivet, with a lump on the end of the mandrel forcing the rivet to expand into the hole, before the mandrel breaks off and leaves the rivet in place.