The event-a cartridge is fired-is fairly simple, easily explained and relationships represented with a set of numbers.
To estimate velocities of a given cartridge case/rifle/bullet over a set of charges, we could measure MV for each of the charges, OR, measure MV at the lowest and highest charges, calculate the slope, and interpolate the MV for each/any charge between.
The latter procedure requires less measuring of velocity.
For example, MV at powder charges of 5.5 to 8.5 grains with a given powder, bullet and cartridge case are of interest. I measure MV 13 times as my minimum sample size. The 13 measures X 7 charges = 92 measurements.
Or, measuring MV 20 times at 5.5 and 8.5 grains = 40 measures, plus 20 measures at 7 grains to check linearity = 60 measures that give a much more precise estimate of MV across the set of charges.
We can estimate MV for other bullets, cartridge cases, and barrel lengths.
With some chrono estimates of MV; we can estimate MV for any cartridge case, charge, and barrel length.
With enough data, we can find the relationships between accuracy and the variables; find out why cast bullets are not as accurate as jacketed and fix the cast bullets.