My case head has a shiny mark on it. Is this a sign of high pressure? My case head has a shiny mark on it. Is this a sign of high pressure? September 4, 2019 Michelle Gallagher Yes. High pressure will set the cartridge back into the bolt face, causing the brass to flow into the ejector hole and leaving a shiny spot on the case head. 0 Newer I’ve worked up to your maximum load in your manual with a standard primer. Can I switch to a magnum primer? View all posts Older Can I purchase factory seconds?