Hi Pete
I chrono every load, run it Sierra Infinity it then gives me an accurate trajectory.
I used to shoot every load at different ranges but now I trust it, as long as you put the correct info into Infinity its always been very accurate.
I shoot various cal's so I also try to tailor the bullet weight/velocity how they shoot a similar trajectory (sad I know).
Not that i regularly take long range shots but if I do, its easy to remember what the trajectory is.
Wayne