I am sure that there is some out there somewhere but I have yet to see hard data of the kind you are talking about. But even if you can get your hands on some of the data the difference between lots of powder, primers, the bullet seating depth and how tight the individual guns chamber is you probably won't be able get get many conclusive results from it. To me the primer shape is a good Canary in the mine as you put it. But I agree that it is a bit like reading chicken bones but unless you want to buy all the real expensive test equipment it is about all we have to go by and we all have to make our own judgements as to what pressure levels we are comfortable with. I load Major 9 some people think that is too much but I am comfortable with it.