Kestrel 4500NV Applied Ballistics Meter - Manual (Page 19)

19
BAllIsTICs sCREEn
parameter is the muzzle velocity of the round (since the
Kestrel is measuring environmental conditions, and the
other specifications of the rifle are well known). By firing
at a target at a range where the round is supersonic
(Mach number greater than 1.2), the muzzle velocity
can be determined from the drop of the bullet at that
range. This works because the drag of the bullet is well
understood and accurately measured in the supersonic
region. Muzzle velocity calibration is the most important
calibration procedure, and should be performed if a
difference in observed and calculated drop is noticed in
the supersonic region.
For longer range shots, in the transonic (Mach number
between 0.8 and 1.2) and subsonic (Mach number
less than 0.8) regions, additional calibration may be
necessary to compensate for variations in the flight of
the bullet. This is where drop scale factors are utilized
to refine the trajectory of the bullet to match observed
drops at longer ranges, but after verifying that the
muzzle velocity has been calibrated at supersonic
range. DSF calibration should be performed if a
difference in observed and calculated drop is noticed
at ranges greater than the calibrated muzzle velocity
range.
Applied Ballistics’ model allows for the input of a
single BC when using a G1 or G7 curve. Once the
appropriate BC (provided by the bullet manufacturer)
has been entered, muzzle velocity calibration should be
performed, followed by DSF Calibration (if necessary) for
longer range shooting. It is recommended that custom
drag curves be used whenever possible for maximum
accuracy.
CAlIBRATIOn & CusTOM DRAG CuRVEs
BALLISTICS SCREEN
The Ballistics screen displays complete information
about the ballistic solution that pertains to the currently
selected target and gun. The only parameter whose
value can be altered in this screen is the “Range” (this can
be done by using and to adjust the value).
• Use or to scroll to a particular parameter.
• Use to enter into a parameter screen for
further information about it or change unit of
measure.
• Use to return to the Ballistics screen.
Note: An R or an L will appear beside each solution to
indicate which side of the target you should aim.
APPLIED BALLIstIcs' sIgnAturE fEAturEs
AUTOMATEd BALLISTICS CALIBRATION &
CUSTOM dRAG CURVES
In an ideal world, shooters would go into the field
knowing exactly how their chosen combination of
gun and ammunition will perform, calculated ballistic
solutions would always be correct, and a properly
delivered shot would always hit the target. In the real
world, ballistic data is often imperfect, and even well
delivered shots often miss. The best way to deal with
this is to allow ballistic parameters to be adjusted to
reflect what is actually observed. When this is done
correctly, overall accuracy can be significantly enhanced.
Ballistics calibration is used to calibrate the inputs of
the ballistic model to match the actual rifle and round
used for shooting. In particular, the most significant