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Sight Settings and Adjustments
After the ballistics and trajectory have been calculated, a Point-Blank-Range-Zero may be calculated from this page. Point-Blank-Range is a concept useful in hunting situations where sight adjustments are not practical..
The point blank range may be defined as the distance out to which a shooter can hold directly on the target or game animal and be assured of a bullet strike within the vital zone of that target or animal.
At distances closer than the point blank range, the bullet will not rise above one half the diameter of the vital zone above the line of sight or fall below the line of sight more than one half of the diameter of the vital zone.
To calculate the point blank range, enter a value that is one half the diameter of the desired vital zone into the first entry field and then select the "Calculate the Point Blank Range" button.
After the calculations, the distance at which the bullet first crosses the line of sight will be indicated in the L.O.S. window.
The distance to the point where the bullet is at the highest point in the trajectory will be shown in the Maximum Height window
The range at which the sights should be zeroed in order to facilitate this procedure is shown in the Point-Blank-Range window.
The range at which the bullet will be at one half the radius of the vital zone below the line of sight is shown in the Maximum-Point-Blank-Range window.
If the selected sight configuration is a " fixed" sight, then no sight adjustment window will be opened.
Selection of an Adjustable sight configuration will show a window displaying the newly calculated ranges in addition to the previously selected ranges, along with the bullet path, minutes-of-angle and sight adjustment graduations used to zero at each range.
A 'Scopesight selection shows a window indicating the number of clicks or dial graduations to change the zero to any indicated range.
A Vernier Sights selection cause two windows to appear, as shown above, with the associated readings and adjustments.
Different values may be repeatedly entered and calculated without having to re-calculate the initial trajectory.
When values are entered into the range windows above, those same values are also entered into the Initial Databox on the Data EntryHlp_Precision_Ballistics
Check the "Show Chart" checkbox to display a graph of the Point Blank Range Trajectory.
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