I have a query concerning the maximum range of 5V27U and 5V27D missiles. After extended testing I ended up with the fact that missile's actual maximum range is about 22km only against high altitude targets. Usually the longest range kill can be seen in the middle of the 20-25 km area in range indicator of the fire control panel as seen below.



However the displayed range in fire control panel depicts the length of a "line" which connects the fire control radar with the target, right?

Therefore the instrumented range is different than the horizontal range right?

In the plotting board screen where the range ring (maximum horizontal range) of the battery can be seen, I calculated the radius for S-125M1 which is about 22km.

A simple graph could be like this:



Normally the maximum range should be higher than horizontal range as the hypotenuse of the triangle but in many cases their values are very close. Why this happens?

Many sites state that maximum range for S-125M/M1 is 25km. Is this the instrumented range or the horizontal range?

Additionally I haven't seen any differences between 5V27U and 5V27D in terms of range. They seem to have almost equal range.