Speaking with the powder tech I did exactly as he said. Use the load data for IMR 4350. I have been for everything. It meters better/does not shear cylinders like 4350. I do not hit pressure indicators as soon as with imr4350. (Not all barrels are the same)
I like it a lot because it doesn't use as much case capacity as 4350 and thus far I do not have anything but good to say about it!

Shortly I will have the new 338 stretch wildcat barrel and the idea came with the intent to shoot Rel 17. Improved WSM case (all) now holds the same powder capacity as the 338 Win Mag.

Neal