Well i have the bimotion head program. I know jts just the guy who made its opinion on what is what. I didnt think about the inconsistent radius of the whole dome of the piston. It just asks in the program a piston height. By using the bore of the of the piston and the height of the dome in a spherical cap volume calculator It seems to be around 18cc. Adding that to the dome I was playing around with it adds up to be the dome cc uninstalled would be  a 57cc dome. And 14.2 CR.

Most of the compression ratio calculators and formulas for head geometry do not account for the volume that is above the top ring between the piston and cylinder wall. 

I could use Calculus and calculate the exact volumes, but it takes much longer to accurately measure all of the dimensions that is needed to put into the equations than it does to use the procedure I gave in a former post