How
does it work? One of three ways, but simple..
a.
The most accurate method is to input the cosine number into
your ballistic software; i.e. Exbal Ballistic Targeting Software
or Field Firing Solutions, that runs on either your home PC,
Pocket PC or Palm Pilot. This is because the software takes
into account the trigonomics of the fact that the bullet will
still travel the full distance to target, and maintain a similar
time of flight.
b.
Method #2, is to multiply the cosine number to your MILRAD
or MOA hold for your distance to target as indicated on your
data card. For example, if your moa hold for 600 yards is
11 moa, and .87 is indicated by the ACI, you would then multiply
.87 X 11moa, and obtain a corrected for gravity distance of
9.57 moa. This is fairly accurate, (Caliber Specific) although
not as accurate as utilizing ballistic software. This is called
the "Improved Rifleman Method."
c.
Method #3, is to multiply the cosine number to your sloped
distance. This will deliver the flat line distance to target,
or what we call the bottom leg of the triangle.
If
you experiment with your ballistic software, you will find
that there can be as much as eight (8) MOA difference between
method #1 and method #3. Method #1 is the most accurate &
preferred method.
Now,
adjust the sight elevation knob (come-ups) on your scope,
for the "corrected range".