Vortex Optics RAZOR HD GEN II 3-18X50 RIFLESCOPE - Manual (Page 3)

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RETICL E
r
eTicle
Reticle Focal Plane
All riflescope reticles can be termed either first focal plane (FFP)
or second focal plane (SFP), depending upon their internal location
within the riflescope. This Razor HD Gen II riflescope features a
first focal plane reticle.
First focal plane (FFP) reticles are located within the riflescope
near the windage and elevation turrets in front of the image-
erecting and magnifying lenses. This style of reticle will visually
grow and shrink as you change the magnification. The advantage
of an FFP reticle is that the reticle subtensions used for ranging,
holdovers, and wind drift corrections are consistent at all
magnifications. Usually, the reticle will appear heavier at higher
magnifications and finer at lower magnifications.
MOA and MRAD Adjustments
Depending on which version you have purchased, your Razor HD
riflescope will feature adjustments and reticles scaled in MOAs or mrads.
Both minute-of-angle (MOA) and milliradian (mrad) unit of arc scales
are equally effective when ranging or adjusting riflescope for bullet
trajectory.
MOA Adjustments
MOA unit of arc measurements are based on degrees and minutes. There
are 360 degrees in a circle and 60 minutes in a degree for a total of 21,600
minutes (MOA) in a circle. A minute of angle will subtend 1.05 inches
at a distance of 100 yards (29.1 mm at 100 meters). Razor HD riflescopes
with MOA adjustments use .25 minute clicks which subtend .26 inches at
100 yards (7.3 mm at a 100 meters), .52 inches at 200 yards (14.6 mm at
200 meters), .78 inches at 300 yards (21.9 at 300 meters), etc.
MRAD Adjustments
Mrad unit of arc measurements are based on the radian. A radian is the
angle subtended at the center of a circle by an arc that is equal in length
to the radius of the circle. There are 6.283 radians in all circles and 1000
milliradian in a radian for a total of 6283 milliradians (mrads) in a circle.
An mrad will subtend 3.6 inches at a distance of 100 yards (10 cm at 100
meters). Razor HD riflescopes with mrad adjustments use .1 mrad clicks
which subtend .36 inches at 100 yards (1 cm at 100 meters) .72 inches
at 200 yards (2 cm at 200 meters), 1.08 inches at 300 yards (3 cm at 300
meters), etc.
“1 Click = 0.25 MOA”
MOA Models
“1 Click = 0.1 MRAD”
MRAD Models