Very interesting thread. Thank you everyone for sharing.
One question. Why is powder charge weight so critical if ES isn't?
0.1 grain of powder makes about 9fps difference in a 220 Swift with 40 gr bullets. That's the extreme.
In 6.5 mm with 150 gr bullets it's about 5 fps per 0.1 gr.
This makes me realize I need to bear down on getting charge weight close. However, digital scales can drift and that makes me nervous about throwing a dangerous charge. And spending $1,000 for a powder scale is a bit much for many. My balance beam type isn't very accurate, but it will keep me out of danger, I think.