Can you fire guns in Space?

Most of us will say no. Because from our early school days we know fire needs oxygen to burn. So when you are in the atmosphere less void of space, there is no way to ignite gunpowder to fire a bullet, right? Wrong. The explosion that fires a bullet does require oxygen for combustion, but it doesn’t draw it solely from the air. Rather, some oxygen comes from an ingredient in the gunpowder itself, called saltpeter (Potassium nitrate). The spark produced when the gun’s hammer strikes the cartridge ignites the saltpeter and converts the oxygen in it to its gaseous state. The explosion generates a shock wave that propels the bullet out of the gun. It would certainly help if you pack your cartridges with extra saltpeter to get the same pop in space.

But it won’t be all too easy. Remember the guy named Newton? And his popular third law of motion. The kickback of the gunshot that normally throws your arm backward after you fire a round would instead send your entire body flying backwards.
Are you still going to take a shot?

info: popular science.