There tends to be a bit of a step change as soon as the bullet starts to go transonic, around 1340 fps. Instability creeps in, especially if your twist rate is marginal, and the G7 models become less accurate. Bryan Litz has developed Custom Curves for use out to about 3000 meters for ELR which uses dopler radar to measure actual bullet speeds and BC through the zone and out the other side. These curves are available for about 250 different LR bullets now but only on his licensed hardware like the Garmin 701. If shooting inside 800 meters Strelok Pro is very good as most LR bullet/rifle combinations are still supersonic at that range, but if you are stretching out a bit then the Custom Curves give a better solution.