One slip up with the last episode of Firelfy
I know it's nitpicking, but they didn't have to put the gun in a space suit to fire it. Firearm ammunition has an oxidizer mixed in with its propellant. There's no need for an outside oxygen source. So while they got the sound (or lack of) right; they messed up another basic principle.
Lee, (I still think it's a cool show though)