Not to hijack this thread but a colleague of mine that produces ammunition implies the Federal 210M primer. Why, I have no idea as he was seeking not to present me proprietary data. I will use the Lee Hand Priming Instrument Once i get around to utilizing the Feds. Ken, https://winchester-small-pistol-p67689.onzeblog.com/31845358/an-unbiased-view-of-federal-primers-ammunition