The Ninja Epidemic

You toss one of the revolvers your cousin gave you over to Rick, who catches it in mid-air. Each of these weapons has six shots and there are twelve ninjas. You cannot miss.

You pull the trigger on those closest to you and hear Rick doing the same. Ninjas fall before the two of you, one by one, thier swords no match for your fire power. When pulling the triggers no longer result in explosions of gunpowder, Rick and you find three ninjas still living and approaching you with little caution. You're unsure of who missed or how many you missed, but you know that a few shots were missed, and this error may cause the two of you your lives.