Not to hijack this thread but a friend of mine that creates ammunition suggests the Federal 210M primer. Why, I don't know as he was trying not to give me proprietary information. I will use the Lee Hand Priming Software when I get all over to utilizing the Feds. Ken, https://winchester-400-primers-5080123.blog5star.com/32280765/the-definitive-guide-to-federal-large-primers-for-sale