Hmm. The rimless 8X60s are both currently standardized by CIP. The CIP max pressure (the highest pressure permitted for factory ammunition that can be legally sold) is the same for both 8X60 and 8X60S - 4050 BAR, or 58,740 PSI. The case is very similar to, and can be made from .30-06, which also has a CIP MAP of 4050 BAR. Sounds like it should be very similar to the '06 with similar weight bullets to me, as the load data above would seem to show.