The difference in base to shoulder from my old fired brass to new virgin brass is 0.02" . To the best of my knowledge the chamber is headspaced correctly from the base to the belt, and 0.02" is not that far in the world of fireforming. However, my question is can I run my normal load of 68.5 grains of Retumbo in this virgin brass without having problems? The brass is prepped and weight separated 7mm Rem Mag brass necked down to 264". When I was necking down I sized the brass down until I saw where the chamber quit scratching the unsized brass. My bullet is in the lands, so I believe the cartridge is properly supported by the belt and the bullet. So will my brass suffer with full power loads?