Like mentioned before, and above in this thread, some have, and I can say I have run the 6.5CM at higher pressures.
We are talking 2950 fps for a 139 gr bullet, and roughly 1500 rounds through a 26” barrel. It was very accurate, hence I ran it for a while. I’m talking 3-4 rounds out of the brass, and when I had to replace the brass too often I slowed things down to 2850 fps. Another accurate node, and much more friendly on my brass.
The Peak+ ammo will be very interesting to run in an 18”, maybe even 16” barrel and see what velocities it can bring. I think the bigger question at this point is how easily available to get the powder they are using to get those velocities. Most from what I remember were close to compressed loads already, so it’s not like you can stuff more in the case. The brass case was already form fitting to the chamber, so you can’t say the case itself takes the higher pressure, hence the fps gain. That pressure has to be built up somewhere, and the only thing plausible is the powder.
Might have to back track to the 7 BC and see what the guys reloading for it are finding.