I'm so confused it's unreal. What do all the numbers and jargon mean? 30-30, 30-06, .308, 7 mm, WSM, ultra mag etc... I can't make since of it all. Do they make a balistics for dummies book? If so I'm buyin. I checked with a friend who has been an avid hunter for over 30 years and he couldnt tell me either. So can anyone here explain all this to me?