A few years back I bought some old steel flechettes from a military surplus store because they looked cool, and I could use them in a presentation for a history class I was taking at the time (but mostly because they were cool). Recently, I got the idea to send some to the Youtube channel Taofledermaus to load and shoot out of a 12 gauge shotgun. If you haven’t seen his channel before he shoots all sorts of odd things out of a shotgun, including a lot of projectiles that are custom machined by some of his viewers. Many of them aren’t aerodynamic enough to stabilize at supersonic or near-supersonic speeds, and end up tumbling, resulting in poor accuracy and key-holing on impact. But the flechettes I have were made to be projectiles, so maybe they’d do better.