Jent, thank you sincerely for your kind offer but I realy don't need Cerosafe as I do my chamber/throat casting using just candle wax - with perfectly useful results for the purpose. The reason I haven't yet do it for this drilling is lack of time (I just received it from Germany and had to register it right away, and needed caliber info for the registration).
I'm not familiar with 6.5x72R but somewhere I have a round or two of 6.5x70R - the "pencil cartridge". These are old berdan type and are considered collectors items.
-Jani