If I may, your understanding is incorrect. There isn't a this sort of matter a 'really hard' or 'tender' primers. Mil spec primers are magnum quality and less delicate for the firing pin strike. Now what I discovered immediately is these things seat like butter (I use a Lee automobile https://israelvjwhs.bloggadores.com/31237963/the-single-best-strategy-to-use-for-federal-ar-match-primers