My new chrono taught me that my medium test loads exceeded the "book" max fps. I didn't even test the max load, just pulled them.
I found one other guy that was having the same problem. His powder was from the same year as mine. I believe there was a problem with the powder
I was using all the same componets exactly and weighed the charges on 2 different scales.
I feel safer now using the chrony for load development.