Note on Melonite or Nitride Parts
Melonite or Nitride treated barrels and gas blocks have a very hard surface. Standard HSS drill bits that are included with out tools are not hard enough to cut this surface. If you are dimpling or drilling for pinning, you will need hard tooling. I have had mixed luck using cobalt drills. In this application, I recommend using carbide drills. They are substantially higher cost but in the end will save much frustration. We try to keep the #31, 11/64" and 3/16" carbide drills in stock.
Instructional Videos By NSZ85
Gas Block Centers Table: