how about a chisel point on the end of a walking stick? you can use it as a spear in a pinch if you must, but it would also serve lots of other more likely uses like to dig, as a post for shelter, etc. and you would have a handy dandy walking stick. if you were to shop it with metal and pound that into a chisel, i dare say it would last for quite a while. and field expedient repairs can be made with a rock if need be.