I assume your asking about the ELD-X.
I'm in the middle of load development with the 143 grain in my 264WM. I've only done one ladder test using Retumbo. My best result was at the 2950 node with 0.65 MOA. I have another ladder loaded up with H1000 and will shoot those soon. All my seating depths have been at 0.020 jump. I'm using a 1:8 twist 26" benchmark barrel.
Also working up a 300WSM load using the 200 grain. Getting 2850fps and 0.50 MOA using H4831SC. I haven't done any seating depth work yet so this may be a very good load in my rifle when done.
I have the 212 and 220 grain for my 300RUM using a 27" benchmark 9.3 twist. I haven't loaded anything yet but will start with H1000, Retumbo and Ramshot Magnum. I'll post up results later.