To not hijack this thread but a colleague of mine that creates ammunition indicates the Federal 210M primer. Why, I don't know as he was making an attempt not to give me proprietary data. I'll utilize the Lee Hand Priming tool when I get all over to utilizing the Feds. https://winchester-primers-for-sa13456.uzblog.net/the-definitive-guide-to-federal-large-rifle-magnum-primers-215-45855599