I'll stick my neck out there and make an estimate.
These numbers are based on the dimensions of the bullets, and a database of information I've compiled that relates measured (tested) BC to bullet geometry. This method results in estimates that are typically within +/- 3% of the measured BC.
The BC's are average from 3000 to 1500 fps.
300 grain Tangent (non-VLD) ogive:
estimated G1 BC: 0.749 lb/in^2
estimated G7 BC: 0.384 lb/in^2
300 grain Secant (VLD) ogive:
estimated G1 BC: 0.855 lb/in^2
estimated G7 BC: 0.438 lb/in^2
For best results when doing trajectory calculations for these bullets, use the G7 BC if your program allows.
I'm very curious to test these bullets and see how accurate the estimates are.
-Bryan