It's equally possible - or perhaps moreso - that it comes from the chinese word gun which means 'staff'. Together qiang (spear), dao (sabre), and jian (sword), a gun was known as the 'grandfather of all weapons'.
While popular belief has it that the Chinese invented gunpowder as merely something for fireworks, a less Eurocentric and more accurate look at history shows that gunpowder was in fact used in some ancient Chinese weapons (bombs, early torpedos, etc.)
Consider that early guns carried by infantry were basically pike staffs that fired bullets.
Commenting by HaloScan
