Destin from Smarter Every Day captured high-speed images of both a revolver and an automatic pistol discharging underwater; the water perfectly captures and renders visible the gas forces at work in the system (and makes for a beautiful picture).
I performed an experiment to see what the differences were between semi-automatic pistols and revolvers. The advantage of shooting under water is that you can see the boundary of the gas flow fields almost perfectly.
Instead of saving for my kids' college, I make videos using the money I would have saved.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.