To establish your "come up" chart you can use a ballistics calculator such as
JBM - Calculations - Trajectory
This will give you a first approximation of your trajectory. You take that chart to your long distance range and shoot your rifle with your load and make corrections to the "predicted" values by replacing them with the real values.
When you are done shooting you go back to JBM and rework your data. Typically the BC will not be as large of a number as the factory said. So with a little fiddling of numbers and tweaking, you will then have the factors that fit your rifle and your load for the temperature and conditions that you fired the data for. You can then use that to make drop charts for other temperatures and elevations.