I run into this with my long range muzzle loader slug guns when shooting out to 600 or more yards. Here is what my mentor said to do and he has been the National black powder cartridge champion several times shooting out to 1000 yards.
- Gather all your ballistic information and go to a website such as JBM Ballistics at:
JBM - Calculations - Trajectory then enter the info. Big items are bullet velocity and how efficient it is.
- Set where you want zero to be set at, in your case 100 yards. I use 50 to start with.
- Take the results and print it out and put in your dope book.
- Figure how scope #clicks affect impact at different distances and put in the dope book. For example my Unertl 20X scope with mounts 7.2 inches apart give 1/4 MOA per click. Since mine is in MOA the actual distance impact changes at different ranges is different. Modern scopes are waaaaaaay easier for adjustments.