Do you know what your coal is with the 75gr eldm touching the lands? What kind of jump have you had success with? I am supposed to have the long range chamber in mine but the 75gr eldm seems to be seated pretty deep in the case at the lands.The mag will let you load long.
24.6 gr Varget under a 77 gr TMK at 2.480 oal got me an easy 2900 with a 5.5 SD, 75 ELD was almost exactly the same so that’s pretty much my recipe for the entire 77 class of bullets.
Not super fast but consistent and Lapua brass should last a very long time. It shot so well I honesty didn’t care to do anymore load dev and ran that. It’s fun to shoot a heavy 223 past 500.
Even my AR load shot like a dream. 23.2 XBR under a 75 bthp loaded to mag length in LC02 brass.
Start low and work to it.