I would ask the Jeff Cooper question: "What's it for?"
My 6.5-'06 is a 6.5X63, but built on a narrower case (same head size as the 9.3X62 or 9.3X66).
The .376 Steyr was also developed from the 9.3X64 case, here going from 9.3mm to 9.5mm and shortening the case from 64 to 60 mm.
There is some wildcat interest in the 6.5 on the wide, short case so short actions can be used. My current idea for a "fave" is a 6.5 RCM. I have not tried one of these, so my theory might not survive the reality test.
I like 6.5s too.
jim
