Mike. Thanks for your reply and the Waidmannsheil reference. I've been a member of the GGCA since its founding but when I read your article, I didn't have the 10.5X47 rifle. For any readers wanting to review this article, it is in Summer 2011 issue (not Spring).
The rim is thick at .095". My case length measurement of 1.77" does not include the rim which would make the correct case length 1.86". The groove diameter is .417".
I have another old combination gun that is chambered for the 9.5X47r and came with 18 rounds of ammo formed from 45-70 as you suggested. I was originally going to turn 6 cases for test firing but I'll check the 9.5X47r rims and if thick enough, fire form a few cases just to test fire the drilling.
Otto
