If they weren't 'pressurized', the very high pressures reached in the combustion would destroy the gun; atmospheric pressure is negligible, in comparison.



Sorry I don't think I made myself clear. When I said bullets arn't pressurised containers what I meant was that the propellant would be exposed to the vacum.Obviously a firearm is capable of withstanding the pressure of the explosion within its barrel when fired within a pressure of 1 atmosphere. Pressure inside the weapon only becomes a safety issue when the atmospheric pressure the weapon is being used in is increased, for example underwater.My argument runs that as atmospheric pressure decreases, the power of the explosion within the bullet decreases with it, to the point that in a vacum, the absence of atmospheric pressure will totally inhibit the explosive reaction need for the bullet to be fired from the gun.It should probably be stated at this point that we were talking about real, commercially available firearms, not hypothetical ones. I firmly believe it would be possible to engineer solutions to all of the problems associated with firing a gun in space, it's just no-ones gone on record as having done it yet. Probably because there's no commercially viable reason to do so.