I have been running 45'ish grains RL15, Lapua brass and 155 scenars. Haven't chrono'd yet but shooting 1/2-3/4" in my Montana and to the same impact as 150 TTSXs. Haven't tried 4064 yet.
When I worked up a load for 155gr Scenars, this charge is what provided the best accuracy for me. Shot a five shot group with it just the other day that measured in the .3s. Velocity is 2870ish.
John