Look at the distance between the center of your scope and the barrel. When the bullet leaves the barrel, it is that far below what you are looking at through the crosshairs. Whatever range you have your gun zeroed at, between the gun and that distance, the bullet is belowwhat your crosshairs are onrising towardsthat zeroed range. At very close range your bullet could be an inch and a half low which would take you out of a brain sized target. Naturally the position of the deer's head would determine what the bulletwill strike. From the side thebrain cavity isbetween the eye and the earand about 1 3/4" highby 2 3/4" long. That is your target so holding crosshairs 1/2" above it's hairline should be the medicine for very close range. Hope this helps.