Semi-related ...
We all know oxygen is part of most combustion process.
So the question came up? If a space walking astronaut fires your standard handgun in space. Will the gunpowder ignite and fire the projectile ? Or will the lack of air impact and prevent the gunpowder from igniting ?
No different than rocket engine combustion. The fuels use a propellant and an oxidizer. They don’t depend on oxygen from the surroundings.
Same with firearms propellants. Old fashioned “gunpowder” consists of a mixture of sulfur (S), charcoal (C), and potassium nitrate (saltpeter, KNO3). The sulfur and charcoal act as fuels while the saltpeter is the oxidizer.
A cartridge will fire underwater. No external oxygen is needed.
But a shooter in space would get a very bad surprise if he failed to account for the kick.
Gunpowder and other cartridge loads are self contained in terms of oxidizer in the propellant. Therefore, they will operate properly in the vacuum of space.
To answer your question, you don’t actually need gaseous oxygen for combustion, but if you don’t have that you need some other oxidizer, which is usually a chemical that releases oxygen as part of a reaction with your fuel source.
Gunpowder already contains an oxidizer in the form of saltpetre, or potassium nitrate, so it should still work in outer space. However, if you fire your gun up there you are essentially setting off a very small solid rocket engine, so it will potentially mess up your orbit!
The gun will fire. Gunpowder does not require oxygen or the presence of atmosphere in order to burn. Gunpowder is an explosive based upon nitroglycerin, which does not not burn in the traditional sense. It decomposes into gasses very quickly, adding heat from the broken chemical bonds. A gun can be fired under water.