I had the same issue until a few months back, but you'll be pretty close.
Say my software says 5.6 mils for 800 yards and it's my first time shooting that far. I'd dial my scope, backoff my power, and squeeze off an accurate shot while trying to see where the bullet landed, run the bolt after you see the impact. I than measure that miss in my reticle and dial it into the scope. So if my round lands .4 mils low and .4 mils right, I'd dial to 6.0 and hold .4 mils left for wind.
I hope that makes sense. For the longest time I only had 300 yards to practice and matches would be my day to collect dope. Who cares about the score as long as your improving.