So, I was just idly thinking about the way powder burns and the variation in the amount of air space in different loads, and therefore different amounts of oxygen available for combustion. It didn't seem like much so I was wondering, does smokeless powder, and the primer for that matter, contain a component that supports combustion? In other words, if a rifle was fired in a vacuum, assuming the cartridge had been evacuated of air, would it fire? I guess it could be fairly easily tested by charging a cartridge with nitrogen also. And yes, I was just day dreaming about how all of this would influence the shot.