Have you tried putting the cups on the Bb, up tight with the PW cartridge shell, not in the frame and then measuring the outside size of the cups.
Then plop it all back in the shell and tighten it up and measure again?
Sorry I hope this isnt telling you how to suck eggs.
Have you tried putting the cups on the Bb, up tight with the PW cartridge shell, not in the frame and then measuring the outside size of the cups.
Then plop it all back in the shell and tighten it up and measure again?
Sorry I hope this isnt telling you how to suck eggs.