[Unclenick]

Board member Hummer70 said that when he was a test director at Aberdeen Proving Grounds, they used copper slugs in a fixture to test firing pin energy. The steel fixture was like a headspace gauge but with a primer pocket with a solid floor. A copper slug was set into the pocket and the fixture was chambered and the trigger pulled. The slug was indented by the firing pin (already checked for adequate protrusion) and the depth of the resulting indentation in the copper was measured to determine energy. I assume the slug maker had the equivalent of a copper crusher tarage table for the indentations for depth vs. firing pin energy.