ORIGINAL: spaniel

Actually, you don't even need the BC -- it is a relatively meaningless and soft number (changes with velocity etc). I have seen few on the internet for ML bullets that generated accurate trajectories with what I saw on the range.

I take a slightly different approach. I get my muzzle velocity, zero the gun at normal range, then check the actual drop at a second range. For example, last summer I zeroed my new scope at 100 yards, getting my MV off the chrony, then aimed dead-on at 200 and shot another nice, tight group. I measured the drop from point-of-aim then went back to the ballistics program and entered a 100-yd zero, my MV, and my best guess for BC. I then adjusted the BC entry until the trajectory the program spit out for 200yd matched what I had just shot on the range. Remember, what is important is an accurate prediction of trajectory, not that the BC you use matches any reported BC for that bullet; BC is only a means to an end.

Low and behold, when I went back out and shot at 300 yds I was withing 1/2 MOA of what the program predicted. I was about 3/4 MOA off at 400 yds I think -- more than enough to get on the paper and adjust.

A ballistics program is NEVER a substitute for actually shooting at every range you plan on shooting at game with a ML. For whatever reason I find that the programs are usually spot-on for centerfire but not as reliable for ML predictions.