|Photo by Ivan Freaner, at sxc.hu|
Can damaged bullet-proof glass stand up to normal air pressure against a hard vacuum on the other side? I don't know. But I don't think it's unreasonable to say that such a thing could be built, right here, with today's technology.
It's probably expensive. It's probably heavy. Those are both problems when you're trying to put ships into space, but it's a good thing science fiction isn't limited to today's technology.
There's a good reason that you wouldn't want to go into space in anything that wasn't a minimum of bullet-proof, though: micro-meteorites. These are small rocks, generally less than a gram (smaller than bullets) but they travel at anything from one to eighty kilometers a second (0.6 to almost 50 miles a second, so even the slow ones are doing over 3100 f/s).
Ordinary meteoroids are up to one meter (about a yard) in diameter and have been recorded at speeds of up to 26 miles/s (42 km/s). You could run into one of those moving at bullet velocities, certainly.
Getting back to gunpowder weapons, though, I think they're reasonable enough on a spaceship once you take these factors into account. One could go to the trouble to invent a laser gun or some kind of energy blaster, but consider:
- Handheld gunpowder weapons already have a good 400 years of technological development behind them and a proven track record of efficient killing. The science and physics are well understood.
- Yes, gunpowder will burn in a vacuum. The oxygen it needs is already bound up in the molecules.
- Yes, automatics can be modified to function in zero gravity.
- Recoil can be minimized, or (I would guess) managed in such a way to distribute the force and cancel itself out. As much as possible. I've tried to have my characters "use" the generated force to their advantage.
- They make loud noises and are scary. Yes, that sounds dumb but the intimidation factor should never be overlooked. It's why pistols in television shootouts are loud as shotgun blasts.
- And to address a pet peeve: they are far easier to use than a knife or, God forbid, a sword. A four-year-old can kill someone with a gun. Swords take years to master, and whenever one gets pulled in science fiction I roll my eyes.