You are perhaps confusing the 9x57 with the 9,3x57. The 9mm has a nominal bore size of .356" (Grooves 0.356", lands 0.345").
Both the 9.3x57 and 9,3x62, as well as the 9,3x64 and 9,3x70 have the same bore size 0.365". The lands are 0.354".
Yes, that is where the confusion was. I will be saving this information.
