G1 or G7 March 13, 2018, 02:14:55 PM Need guidance on which to use G1 or G7. I will be shooting Hornady 140 grain ELD match and the Hornady reloading manual lists a different BC for G1 or G7 for this bullet. I'm getting ready to put information into a ballistics calculator and don't know which I should use or if it even make a difference. Why do you need 2 different BC's . Easy to understand explanations appreciated Thanks in advance for your replies.