
That's testing an AC5 at approximately 1700 meters (it's max range) (rangefinder shows the ground behind the Cat, when place the pip on it, it was at 1693 meters)
The Catapult in the image stands 20 pixels tall (from toes to top of missile pods). From the center of the lower reticle, to the impact point is 22 pixels. A mere 1/4 inch in the image, which translates to a LOT more:
Since the Catapult is approximately 17 meters tall to the top of its pod:

We can say each pixel represents close to .85 meters, meaning at that range (1700 meters, or just over 1 mile) the ac5 had a bullet drop of approximately 18.7 meters (or 61.35 ft)!
If needed or desired, I can go and get approximate max range drops for the other ballistics. Just noted how often people on here lament how the ballistics need bullet drop drop to feel more realistic. I would say that a full mech height worth of drop at it's max range is pretty significant, myself.