When I was load developing for my 7mmRM and H1000, I found the node and did 0.2 grains either side of the mid point. I repeated the test 3 or 4 times on different days and all gave the same performance. This was after the seating depth test. Smaller cases like the .243, .2 grains made a difference. Smaller yet, 204 Ruger, 0.1 grains made a difference. Basically, 3% to 5% of case volume was the edge of performance change.