in this clip I liked its easy to understand explanation.
I myself do a 200 zero not a 300m by shooting approx 1.8 inches low at 25m.
This way I dont need to adjust height even in the 140-200 range that is problematic with a 300m zero.
I remember back in the day as a young troop not understanding why my perfectly zeroed M16 would miss just at 150 and 200m.
Now I understand why.. My Drill sergeants had failed to tell me to aim low at those distances woth a 300m zeroed rifle ( if POI=POA at 25m than that's a 300m zero)
With a 50/200m zero I never have to worry about aiming high or low unless I approach 300m or more.
And then its kinda intuitive to me to raise my POA
