We've got MV for 2 bullets (40 and 55 gr)and 2 powder charges, (7 and 8.5 gr) for a certain barrel, (Shilen 22-250).
We know that MV and powder charge are linear from 5.5 to 8.5 gr., so we can easily estimate MV for all charges from 5.5-8.5 gr.
We know that MV varies .8% / inch of barrel length, sdo we can easily estimate MV for any barrel length. We know that the slope of MV vs. case volume varies, as does MV; so we can easily estimate MV for any cartridge case.
We know that the slope of MV vs powder charge varies with bullet weight, so we can easily estimate MV for any bullet, cartridge, and powder charge from 5.5-8.5 gr. Titegroup. ANY!