Any help would be appreciated. Looking for information that Mule Deer has posted several times. It's regarding a useful rule of thumb about the amount of velocity increase you can expect to achieve for a given increase in case capacity.
I have horrible mojo trying to use the search function...

TIA

IIRC, it works on the basis of percentages. If you increase case capacity, one fourth of the powder percentage increase will be the velocity percentage increase. For example, if you increase the case capacity 4%, you increase the velocity by 1%, given that you are using a powder that produces the most optimal velocity, and you are using the same operating pressure. If you increase the powder capacity by 10%, you increase the velocity by about 2.5%, again using the most optimal powder at the same pressure.