Thanks Eric,
I've been using this FREE program for a couple of weeks on both Windows and Mac OSX (.jar version, which is JAVA, which runs on both OSs). It is accurate as JBM online if your inputs are correct for G7 BC and atmospherics. Saves a text file to print out, which can be modified before printing in a Text Editor to insert the header and print only what you want for a ballistics card. As a free program, there isn't a database built in for bullet BCs, however, I use the G7 BCs from Bryan Litz's outstanding book, Applied Ballistics For Long Range Shooting.

Highly recommended (price is right).