That’s an excellent issue, Ted. I’m unsure. Here is a pair samples of what I’ve read in numerous locations to the Federal 210 vs Federal 210M variations: Checking out my stock of primers, I am most affordable with SPP at just about 7K. I shoot a small fraction from the https://federalprimersfor9mm91345.iyublog.com/31208681/federal-champion-210-large-rifle-primers-things-to-know-before-you-buy