A "drop point" shaper is not a true file it is more of a rasp. they are very easy to make either from an old good quality file or from a 3/8 inch plain edge wood chisel. Either method you choose you will have to break the metal's temper so it will be soft enough for shaping. I did give instructions on how to break the temper of a file the method for the chisel is the same, then re harden it after shaping when I made two guncase turnscrews posting. I prefer the wood chisel because the top and bottom surfaces are smooth from the start it will also have a fitted handle with a file you have to make at least one surface smooth. Shape the end of either item you use round I prefer a lollypop shape rather than a plane round end because a waste gives better access. the cutting edge is just a number of straight cut teeth using a triangular needle file or a junior hacksaw then re hardened then tempered to pale straw.
