I really don't know what the new cartridge is capable of DF. I do know that a 264 Win is capable of 3250 with the 140's with at least 2 powders I've used. JohnBurns gets 3250 with Retumbo, so that makes 3.
My loads are way below pressures I hit with US-869 and the 130's at about 3175.
The only powders I've used in the .264 that were tough to get enough in the case to even start showing an ejector mark or some sticky bolt are RL-33 and WC-872. RL-33 behaved better in my estimation, that's why I've got 15 pounds and have loaded up every piece of brass I own with that load. After a long time trying with 3 barrels, it's the best I though I could do and I settled there.
I'm gonna bet WC will get better velocities than anything anyone has tried up to now in the 26
