![Primer cups, the basic concept works now with 0% fail rate, but the unevenness of cups is persistent, idk if it's because of very fine die misalignment, trimming solves problem though, more Primer cups, the basic concept works now with 0% fail rate, but the unevenness of cups is persistent, idk if it's because of very fine die misalignment, trimming solves problem though, more](https://i.redd.it/47ez10m63tq91.jpg)
Primer cups, the basic concept works now with 0% fail rate, but the unevenness of cups is persistent, idk if it's because of very fine die misalignment, trimming solves problem though, more
![Side and top views of a percussion cap, comprised of the primer cup,... | Download Scientific Diagram Side and top views of a percussion cap, comprised of the primer cup,... | Download Scientific Diagram](https://www.researchgate.net/publication/336659708/figure/fig2/AS:815522039996427@1571447014540/Side-and-top-views-of-a-percussion-cap-comprised-of-the-primer-cup-anvil-and-primer-mix_Q320.jpg)
Side and top views of a percussion cap, comprised of the primer cup,... | Download Scientific Diagram
Side and top views of a percussion cap, comprised of the primer cup,... | Download Scientific Diagram
![Why do they call it a "battery" cup primer? - General Ammunition Discussion - International Ammunition Association Web Forum Why do they call it a "battery" cup primer? - General Ammunition Discussion - International Ammunition Association Web Forum](https://global.discourse-cdn.com/business6/uploads/cartridgecollectors/optimized/3X/3/7/3726f12a23d1f194bae788502083c0cc18b28e04_2_690x215.jpeg)