Got a Real-World Weapon or Armor Question? Mk. VI

[Diamondeye]

2. Would a modern assault rifle function in a vacuum? (I just re-watched the episode "Our Mrs. Reynolds" from Firefly) Would it be good for one shot? Multiple?

If the ammunition had sufficient oxygen content for combustion, or if there were some other way of supplying oxygen to it, then yes it would be good for at least one shot. As to whether the gas-operated recoil system would work I'm less certain. You could still manually **** it after each shot though.