We could always go back to the Puckle gun with its square bullets, designed for killing moslems.
http://en.wikipedia.org/wiki/Puckle_gun
Puckle demonstrated two versions of the basic design: one, intended for use against Christian enemies, fired conventional round bullets, while the second variant, designed to be used against the Muslim Turks, fired square bullets. The square bullets were considered to be more damaging. They would, according to the patent, convince the Turks of the “benefits of Christian civilization.” The square bullets, however, were discontinued due to their unpredictable flight pattern.