Originally Posted by luddite
It really depends how high the scope is above the barrel.
The higher the scope the further out will be the perceived top of the trajectory, also less clicks will be needed at the longer ranges.
My zero for Hft, low scope, is 25 yards.
My main zero for my FT guns is 32 yards.
Top of the trajectory is the top of the trajectory. Perception doesn't enter the equation, only physics.
You can choose to align your sighting system with this point or with another point. If you choose a point lower than apogee, the sighted rig will be "zeroed" at two ranges.
When set to touch the trajectory at a single point, a higher sight line relative to the bore will touch the trajectory curve further away than a lower one.
... is what you meant.