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I checked my book (first edition).
Cases should be new and unfired (I was wrong above).
My book says if you get 0.0005 inches expansion (Yes, that is the correct number of zeros), back off by 1...

I think that's more than my Nick Harvey manual recommended, I'll check later.
I think it also said cases should have been fired previously (i.e. not new) as there is always expansion at the first...