In my experience, the ACOG is very accurate and can be quite effective for estimating ranges. Remember, we are talking about estimation, which is all you really need for tactical observations in a platoon.
Shooting center-of-mass at a body sized target up to 500m does not require more. And it is certainly good enough for field intelligence and identifying distant objects for the commander/support fire which is a major advantage that the kala brings to the squad/platoon
In Lebanon2, with the 4xAquila, I was able to detect and correctly estimate the range the Givati battalion moving in front of us at 600m away
Here are files I made that show the actual milrad (alpiot) measurements of the Trijicon ACOG and 4xAquila reticle lines that I calculated and various extra ways to use the hash marks for estimating range.
Note that in graphic above, the 400m and 500m POA marked (2nd & 4th crosshairs) are for the 20inch barrel A3 rifle.
Horizontal measurements are for the width of the mark. Inner vertical measurements are for the distance between the marks, outer is the accumalative distance from the center.
Size of the target objects that were apparently used to calculate range
Man width = 50cm
Profile width = 30cm
Head length = 25cm
I used for a man's height = 180cm
The following page I use as a pocket guide whenever I'm on miluim
I hope you find these useful. They are based on the original plain crosshair TA01 pattern but should work just as well with the red donut pattern. The original files are higher resolution than I can place here. I can email them to anyone that is interested.
BTW, if anyone is concerned, I got prior permission from the manager to post this information