Re: 308 ballistic charts
Adam...going to a ballistic database or program for data is still only going to get you partial numbers and "guesstimates" for the equation and ultimately, won't get you where you need to be with YOUR rifle in terms of real-world data to get you on target.
I think you will find the BC of the South African 147gr FMJ to be approx. 0.41, BUT you are still going to need an actual, averaged MV reading, atmospheric/environmental data, etc. to get you on track in terms of getting good data back from a ballistics calculator. The only way to get you started correctly is for you to obtain the data for YOUR rifle which means getting (whether buying or borrowing) a chronograph and knowing what you are getting out of your rifle on average.
The only other way to go about it without a chrono, etc., is to shoot your rifle at varying ranges. Start with your zero range (100yds, etc.), then move back in 25yd or 50yd incriments and note the drop you witness (or your required elevation dial-ups to get you on target) between those range intervals, then record them in a log book that you can later use to create a range card.
