What about pointed sticks?
My uncle somehow obtained a shotgun made out of pipes supossedly used by Philippine guerilla fighters during the war. A long section of pipe served as the barrel and had a diameter that held a single 12 guage shotgun shell. A shorter length of pipe of a slightlly larger diameter was affixed to a crude wooden stock which had a firing pin made from a nail pounded into the wooden stock and protruding into the shorter pipe. The weapon was fired by putting a shotgun shell into the end of the “barrel” and ramming it into the shorter pipe. The nail would hit the primer cap and fire the round. My uncle said he tried firing the weapon and while it worked it made an unearthly bang and the barrel became too hot to touch.