At a match, two older guys were talking to a younger guy about reloading (they do, I gather he didn't yet). I was standing just in ear-shot, and thought I heard one of them say "you need a heavy crimp to ensure complete powder combustion". I moved a little closer, and asked if they were talking about roll crimp for revolvers. He said no, even for auto-pistols, "you need a heavy crimp to hold the bullet in place to maximize pressure so you get complete powder burn." I figured it wasn't worth arguing, explaining that heavier crimp will actually reduce neck tension, not to mention the negatives that can result from damaging the bullet (plating/coating), or that these rounds headspace on the case mouth, and a heavy crimp can screw that up, and just walked away from the stupid.