Leupold RX-2800 TBR/W Complete Operating Instructions page 23

TRUE BALLISTIC RANGE (TBR) FOR RIFLES
Gravity has maximum influence on a bullet
when its path is level . When a bullet's path
is angled high or low, gravity has more effect
on velocity and less effect on its path . So
that means the bullet flies on a straighter
path but slower . Meaning that the bullet hits
high when shooting down and up if you use
standard line-of-sight distances .
TBR
YD
20