I stopped fighting the chisels. I use them to lightly space the stiches. I use a short length of an ice pick to push the holes through. I mount it in my small drill press, which I have drilled an 1/8" hole in the edge of the table. This allows me to pass the ice pick tip through as many layers of leather as I need. I run the drill press at a medium speed. You can then easily stitch the sheath using blunt needles, and no fighting to pull the thread through. I also cut a groove for the stitching to lay in after pushing in the holes. A few taps on the finished stitch closes the leather fairly tight, since you did not remove any leather, just "pushed" it out of the way. This gives a nice flush stitch. The blunt needles are great- no blood from the pointed ones, and no need for finger cots!
