I saw the article on whether guns could be fired in space. However, one thing which wasn’t mentioned, is the effect of near vacuum, and the temperature extremes, on the gun’s moving parts. This is especially a problem when it comes to the gun’s lubrication. Basically, the oil may sublimate from the weapon, or in the very least, be negatively affected as the oil loses all its volitiles. I remember reading an article about this somewhere else, but can’t remember where, that a scenario would suggest that a gun when brought out of the airlock would operate fine initially. However, one probably would have to make sure every shot counts, because the gun would quickly jam, likely resulting in total failure of the firearm.
I use a product (Break-Free CLP) that contains teflon, among other things. It should last much longer than straight gun oil. Even in a vacuum, an oil-based lubricant isn’t going to instantly evaporate. It’s going to take a while. A more serious problem may be how the lubricant and parts react to extreme temperatures.
Just to keep all our ducks in a row (it’s much easier to shoot them that way) , the original report was Bricker’s Would a gun work in space?
Those (and some other) problems were discussed in previous thread on that article. Take a look, some good reading there.
And, welcome to the Straight Dope!