There seems to be a number of cartridges out there that have the same designation, which is the case here. The 8x60r you found at Buffalo is for the Kropatchek bolt rifle, and has a longer gradual tapered neck, and different head dimensions. What I am dealing with is a shorter necked case, .470 in the head. The s designation refers to the bore diameter being .323 vs. i or j designation with a bore of .318.

I have the extractor made and fitted to the barrels, and have found a machinist close who has electrode EDM capability. I will have him do pockets in each side to receive the sliding clips to hold the rimless case head. So far so good!

Thanks, Doug