I zeroed mine for 100 yards, which gives me the following POI using M193 ammo:
-1.5" @ 25 yds
-0.7" @ 50
-2" @ 200
-10" @ 300
At 400 yards, the POI comes to about 26-27" below POA, but I've never shot that far with it, and can't even imagine how wind would affect a 55gr projectile at that...