Larry's Use Of The Duplex Crosshair

How to use the Scopes Duplex range-finding reticle. The secret to being able to quickly estimate the range to your target is in knowing the size of your target. Where the crosshairs go from thick to fine is referred to here as an "APEX".  The Scopes duplex or 30/30 range-finding reticle is based on a "APEX to APEX" area of 30 inches at 100 yds @ 4x power. 

The average size buck has a body of 30 inches in scope at 100 yards; so if it appears to fill the point to point area @ 4x power it is 100 yds away.   If it only fills half the area (called "point to crosshair") it is 200 yds away,  and so on,  as shown in the illustration:  The following table shows the target ranges,  based on a 30 inch target at various powers and whether the target fills the "point to point" area or the "point to crosshair" area (ie half the "point to point" area). 

Powers Point to Crosshair Point to Point
3x 150yds 75yds
4x 200yds 100yds
5x 250yds 125yds
6x 300yds 150yds
7x 350yds 175yds
8x 400yds 200yds
9x 450yds 225yds
10x 500yds 250yds
11x 550yds 275yds
12x 600yds 300yds