That’s a great issue, Ted. I’m not sure. Here is a few samples of what I’ve listened to in different places to the Federal 210 vs Federal 210M variations: Considering my stock of primers, I'm lowest with SPP at just above 7K. I shoot a small portion in the rounds https://waylonudaum.blogdigy.com/the-greatest-guide-to-federal-lrm-primers-47651424