Bullet Block Jig. One-inch thick aluminum. Simply bolt a half-inch thick scrap of hardwood to the face using the cap screw, drill from the opposite side through-and-through using any hand-held drill with a 15/64th bit, add a Doorskin bottom, and trim to size against the jig using a saw followed by sanding and a light coat of thinned linseed oil. Easy Peasy. No layout or drill press required for a perfect job. ;)
Each piece requires drilling 65 holes and tapping five sets of threads by hand. I can tell you exactly why the shop who used to make and sell these popular items wholesale in the 20-dollar range discontinued them. ;)
