gerryr
Member
When I made my first Sierras, I dutifully followed the instructions about what drill bit to use, 27/64". I was never pleased with it because the hole was just way too big for the tube. After I got my giant set of HF drill bits, I measured the Sierra tube and discovered that the "Z" drill bit is about as perfect for the Sierra as you can get. I also don't have to use as much epoxy when glueing the tubes in.