The relationship of BC's to caliber does not need to "scaled" for approximation, as there exists a specific relationship, i.e. inversely related to the square of the caliber
Form factor "i" is an absolute magnitude for a specified velocity.
The form factor changes with velocity because the aerodynamic drag of a specific bullet changes at different velocities, particularly in the transonic zone of flight.
PSA.........don't try to type a simple division formula as the algorithm of the forum syntax screws it up !!!!!!
Type it in a Word document and screenshot it, then upload it as an attachment. You are welcome.