Not to hijack this thread but a pal of mine that provides ammunition implies the Federal 210M primer. Why, I don't know as he was striving not to give me proprietary information. I'll make use of the Lee Hand Priming Device Once i get all-around to utilizing the Feds. Ken, https://jaredbnhyj.isblog.net/the-definitive-guide-to-federal-large-rifle-magnum-primers-215-49129375