buckstix,
COTW must be wrong then (not that uncommon), it shows 10.75x68 as having a head diameter of .492". Belted cases usually have a belt diameter of around .532" with a diameter ahead of the belt of around .500". This would leave about .008" to account for. Considering chambers are often .005-.010" larger than the max cartridge diameter (depending on maker) and modern belted cases are pretty thick at the head, turning the belt off and "polishing" the rest off may be enough without swaging the head. Deepening the extractor groove would be necessary in any case. I will admit, depending only on listed dimensions often will not work and it is necessary to have the actual rifle and cases "in hand" to ensure any cartridge case conversion will work. I will also admit that not every handloader has any interest in converting common cartridge cases into uncommon caliber cases. BTW, swaging case heads (actually sizing, swaging is to increase diameter as with bullets) is not as difficult as it would seem, but it does add additional work.
Mike
