Re: Pressure Question...Agree with this?
Of pressure signs, primer appearance is pretty much the least meaningful.
What is meaningful to any reloader is whether brass extracts from the chamber with a 'problem', or not. Typically, with rational load workup, a problem is preceded by several validating 'signs'.
Lookup pressure signs.
Your reloading reference is also validating to what you see. But there are often local factors(like your sizing, barrel, temps, lot of powder/primer, bullet seating, etc) that affect the REAL outcome.
With this, again, the only real problem is just that. And if it's not a problem then it's also just that.
I don't care about flattening primers. In themselves, they don't hurt a thing. They don't mean my pressure is 4Kpsi over somebody's book max(and who cares). They don't directly mean my primer pockets will loosen(a problem). They are one sign.
Now if I'm 2.5gr over several reference source's max, my chrono validates this, my primers are flattening, I have a webring forming, and extraction is getting difficult? It's time to predict a problem in brass life atleast, and how will I manage this?
Well, if my load is performing real damn good, I might live with tossing cases after a few firings. That's one solution many point blank BR shooters adopt(not me).
Otherwise, I'll back off & seek a better load(better for me).
A reloading problem, like accuracy, is locally defined by the reloader. Just use common sense and caution. Stay engaged with it.