I’ve written about this before. I use copper points. Each of my darts are bamboo or river cane and have a 12 inch X 1/2 inch diameter poplar foreshaft. I use 1/4 inch diameter copper rods to make my points. I pound one end of a 1 1/2 inch long piece of copper rod flat, use a cold chisel to cut a point shape into the flatten end, and file it sharp. I drill a 1/4 inch diameter hole into one end of the foreshaft, use a rasp to cone shape the end, glue and insert the rod end of the copper point into the drilled hole, and glue the wood around the point, wrap it cotton string, spread glue on the string, then spin the glued surface into a folded paper towel to smooth it out. After it dries, I glue and insert the other end of the foreshaft into the big end of the dart shaft.
For a better copper point, see http://www.atlatl-darts.com/darts.htm This is AJ Bagg’s web site. He sells bullet swaged copper points that are real easy to mount for about $3 each.