Today’s Non-Sequitur
Quick thoughts: yes, it would fire. As Tommy Lee Jones reminds us, pistols (not just Glocks) can fire underwater, if you’re stupid enough to do so (like you’re performing DIY Shock wave lithotripsy) — they carry their own oxidant.
The bullet would travel faster, too. There would be less drag on the bullet, so it would not slow down as much as it does at one atmosphere. The muzzle velocity would only be epsilon faster, but the overall speed at some arbitrary distance would be higher.
I don’t understand why Danae doesn’t find that interesting.
(Blam! and Ping! not really happening, of course, in that rarefied atmosphere)
Update: the speed to orbit near the surface of the moon is about 1680 m/s. Not achievable with a pistol, but within the capabilities of some advanced weaponry. Escape speed (1.41 times higher) would require a Bull-like supergun.
I suspect the muzzle velocity at Earth’s sea-level is constrained to some small multiple of the speed of sound due to compression of the air ahead of the bullet.
In a vacuum, the energy (velocity^2) should be more proportional to the size of the charge, so I would expect a bullet to travel substantially faster. I bet a high-powered hunting rifle would do the trick (although the site you linked to is down right now, so I’m not entirely sure what the goal is).
Not pushing air down a barrelmakes a supersonic round fired in vacuum exit faster. ~5520 fps needed for surface-skimming lunar orbit. Factory load for a 30-06 150 grain spitzer bullet has muzzle velocity ~2910 fps. .220 Swift/.224 diameter bullets, 40 gr HP gave 4213 fps. .22-.378, a giant .378 Weatherby necked down to .22 with a 19 grain bullet, had a muzzle velocity around 6600 fps. Tremendous barrel erosion quickly ruins the rifle.