The High Point of the Arc
Maximum ordinate is the greatest height a projectile rises above the straight line of sight on its way to a zeroed distance. Midrange trajectory is the closely related figure describing how high the path sits at the halfway point of the flight. Both quantify the curve that every projectile follows and explain why a zero at one distance still leaves the path above the aiming line in between.
Why the Projectile Must Rise
The line of sight is perfectly straight, but the trajectory is a downward-curving arc under gravity. To cross that straight line again at the far zero, the projectile must be launched slightly upward and therefore travel above the line of sight through the middle of its flight. The peak of that rise is the maximum ordinate.
Where the Peak Occurs
Maximum ordinate falls a little past the midpoint of the flight, not exactly at half distance, because the projectile is slowing as it travels. Drag makes the second half of the trip take longer than the first, shifting the highest point of the arc slightly downrange of the geometric center between muzzle and zero.
How It Scales With Zero Distance
Maximum ordinate grows rapidly as the zero distance increases. A short zero produces only a small rise above the sight line, while a long zero forces a much higher arc so the path can reach out to the farther crossing point. This is why extending a zero is not free in terms of how high the projectile travels at intermediate distances.
Why It Matters for Interpretation
Knowing the maximum ordinate tells a reader how far above the aiming line the projectile sits at its highest, which matters when a target sits at an intermediate distance. It also clarifies the meaning of a stated zero, because two figures, the near and far crossings, share the same curve summarized by that peak height.
Worked Example
Imagine a projectile zeroed at 200 yards that rises to a maximum ordinate of about 1.5 inches above the line of sight near 110 yards. A target at that intermediate distance would be struck roughly 1.5 inches high even though the sights are aligned for 200 yards. Push the zero out to 300 yards and the peak might climb to several inches, changing the intermediate holds noticeably.
A Common Misconception
Many readers believe the maximum ordinate occurs exactly at half the zero distance. Because drag slows the projectile and stretches the time spent covering the second half of the path, the true high point sits somewhat beyond the midpoint. Assuming it lands precisely at the center misplaces where the trajectory peaks and misreads the intermediate holds.