I’ve touched on this earlier: the one negative plaguing the 6.5 Swede is that it is normally under-loaded. American factory loads are very wimpy; the European factory loads are a little more powerful, but still somewhat under-loaded. This state of affairs stems from the CIP and SAAMI pressure standards. The European CIP maximum pressure standard is 55,114 piezo PSI for modern firearms. However, it’s hard to see the logic in this as the corresponding pressure standards are 60,191 PSI for the .260 Rem. and 63,091 PSI for the 6.5 Creedmoor. Although CIP cites its 6.5x55 standard for modern firearms, it seems to be driven down by the knowledge that there are all those old military 6.5 Swede rifles out there—the Mauser 94/96s and others—even though, for those rifles, the CIP standard is too high.
According the CIP, if you have a 6.5 Creedmoor, which can be safely loaded to 63,091 PSI, and you rebarrel that action to 6.5x55, you shouldn’t load to that pressure any more. Since the action hasn’t changed, this makes little sense to me.
I suspect that it isn’t just factory-load shooters who’ve been affected by this anomaly, but also handloaders held back by loading data provided by the bullet and powder makers who seem to hold their published maximum loads down to the 55,114 PSI standard.
