I don't give a rats rear about how much difference there is in burn rates, you do not hear this, do not shoot above max MV in and magnum case using a powder charge that only uses 76% of case capacity, I've loaded many, many thousands of rounds, the difference in burn rates isn't that dramatic, I shoot a lot of powder designed for the 20 MM Vulcan cannon, no magnum load that I have ever saw used a less than 85% fill rate to achive max velocity at acceptable pressures, and its a well published fact that your most efficient loads are those using a powder that fills the case to 90% or more, that is in every manual out there. keep insisting that your correct, I'll agree to write it off as more internet hype.
RR