I have a commercial Mauser chambered in 30-06.
The chamber is a bit over sized based on measuring fired brass .471+ at the web. You can see the bulge with the naked eye. I have been shooting mild loads in Mil brass. The barrel shoots great. Has a nice set of folding express sights soldered on. The barrel profile is very close to a Douglas feather weight - so not enough shank to turn down and re-chamber. Wondering if there is enough room (diameter) to rebore to 9.3 mm and chamber in 9.3 X 62

I believe that .471" at the web is still well within the maximum tolerance. Other than the fact that it seems to be on the large side is there any other reason that you want to rebore.