Vortex Impact 850 Manual page 6

Using the HCD Mode
Use the HCD range mode in the following situations:
• Rifle shooting on level ground at any range.
• Rifle shooting out to ranges of 800 yards with mild slopes
(less than 15 degrees).
• Rifle shooting out to ranges of 400 yards with moderate
slopes (15 to 30 degrees).
• For all archery shooting.
Note: See page 12 for method of reading slope degree in
LOS mode.
The displayed HCD yardage number
is corrected for shot angle and needs
no extra user input; shooters simply
use the appropriate level ground bullet
drop and wind adjustment for the range
displayed and shoot. Archers use the
appropriate level ground sight pin for
the range displayed and shoot.
Use 525 yard level
ground drop data to
make shot.
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LOS Mode
The Impact 850's LOS (Line of Sight) mode is intended
®
for rifle shooters who are using slope correcting ballistic
drop data cards, ballistic cell phone applications, or other
ballistic programs and who are shooting at distances beyond
500 yards and with slopes greater than 15 degrees. Most
shooters and archers will not need the LOS mode.
The range number displayed in LOS mode is the actual
line of sight range with no ballistic correction for slope.
Most of the commonly used ballistic devices can provide
independent slope correction for bullet drop data and
require actual line of sight range input. Using the LOS
range when calculating bullet wind drifts under these steep
slope/long range conditions will provide a higher degree of
accuracy than using the HCD range.
To use, simply input the LOS range number into the
electronic device or use the LOS range when referencing
ballistic drop cards with slope correction.
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