RE: 7mm Rem Mag - downgraded?
I don't know about being down to the 7x57 class, but most cartirdges aren't loaded to the pressures they were in the "good ol days". The official story is that modern pressure testing techniques have found many of the older top loads as being over pressure. My newer reloading manuals don't come anywhere near my old books from the 70's. The famous Elmer Keith 44 Mag. load of a 240 grain lead bullet and 21 grains of 2400 is no longer in any of my newer reloading books. It's considered over pressure by today's standards.