I cast my duck call blanks pre-bored and round so only using about 30% of volume you listed, I have also been casting pot call blanks for about 1.5 years now, mine are 4.25 dia x 1.5 thick and sell for $25 for straight cast and little extra when I add wood, beans, corn, pods,coffee, etc. But you are correct on volumes based on the sizes you listed, you can use the Alumilite volume calculator to get it exact.