Vortex Optics VIPER PST 2.5-10X32 FFP RIFLESCOPE User Manual

RIFLESCO PE

RIFLESCOPE

First Focal Plane | Uncapped Turrets

2.5-10 x32 FFP ebr-1 RETICLE

RIFLESCO PE

The Vortex® EBR-1 MOA Reticle

Designed to maximize long distance shooting and ranging abilities, the

TM

EBR-1 MOA reticle for the Viper®PST
used to effectively determine ranges, holdovers, windage corrections
and moving target leads. Ultra precision laser etching on the glass
reticle ensures that minute of angle (MOA) specifi cations can be kept
to the tightest tolerances possible. The fi ne center crosshair subtensions
on the EBR-1 MOA reticle were carefully chosen to provide the
optimum balance between precision aiming and low light visibility.

2.5–10x32 rifl escope can be

Dual Use: Shooting Tactical / Hunting
US Patent 7,937,879

Note: Reticle images shown in this manual are for representation
only—images vary between scope models depending on
magnifi cation and reticle plane.

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MOA Subtensions

The EBR-1 reticle is based on minute-of-angle (MOA) subtensions.

MOA measurements are based on

degrees and minutes: 360 degrees in

a circle, 60 minutes in a degree for a

total of 21,600 minutes. These angular

measurements are used to estimate

range and correct for bullet trajectory

drop in riflescopes. 1 MOA will

correspond to 1.05 inches at a 100 yard

distance, 2.1 inches at 200 yards, 3.15

inches at 300 yards, and so on.

In the Viper PST first focal plane

riflescopes, the listed MOA subtensions

of the EBR-1 reticle are valid at all

magnification levels. This means the

shooter can use the magnification

level most appropriate for the situation

and still have effective holdover and windage reference marks. This is

also extremely valuable in a high-stress situation, as the shooter does

not have to remember to set the scope to one particular magnification

to get valid holdovers—an action necessary with the more common

second focal plane reticles.

Estimating MOA

Although 1 MOA is very

commonly corresponded to

1 inch at 100 yards, this is

not quite correct. 1 MOA at

100 yards equals 1.05 inches.

Calling 1 MOA an inch per

100 yards may be acceptable

at shorter distances, but it

will cause a five percent error

in ranging and holdover

adjustments. This will result

in missed shots at longer

distances.

EBR-1 MOA Reticle Subtensions

Heavy crosshair
subtends 5 MOA

5 MOA 2 MOA

RIFLESCO PE

Fine crosshair
subtends .2 MOA

Gap subtends
10 MOA

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Ranging

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MOA measurements are very effective for ranging using a simple formula.

To use this formula, the shooter needs to know the size of the target or

nearby object in inches.

MOA Ranging Formula

Target Size (Inches) x 95.5

Measured MOAs

Range (Yards)

=

Using either the vertical or horizontal MOA scale, place the reticle on

a target of known dimensions and read the number of MOAs spanned.

You will obtain maximum accuracy in ranging by calculating exact

MOA measurements. MOAs should be estimated in 1/4s if possible.

Accurate measuring will depend on a very steady hold. The rifle should

be solidly braced using a rest, bipod or sling when measuring. Once

you have an accurate MOA reading, use the formula to calculate the

distance.

Note: In the MOA ranging formula, a shooter may substitute 100 for

95.5 in the interest of speedier calculations. Be aware that this will

produce a five percent over-estimation error of the yardage distance

obtained.

Example

Ranging a 6-foot target (72 inches) at 10 MOAs yields 688 yards.

72 x 95.5

10 MOA

=

688 Yards

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Elevation Holdovers

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Once the distance has been calculated using the EBR-1 MOA reticle

or a laser rangefinder, the EBR-1 can be used for rapid holdover

correction for bullet drop of the cartridge being used. To get the most

benefit out of the EBR-1 equipped riflescope, Vortex Optics highly

recommends shooters learn their bullet drop numbers in MOAs rather

than inches.

Since the EBR-1 reticle is scaled in 2 MOA increments, it is an easy job

to quickly select the correct drop reference line once the shooter knows

the bullet drops in MOAs. If the shooter prefers to dial come ups for

bullet drop using the elevation knob, knowing bullet drops in MOAs

rather than inches will allow for much faster adjustments as the MOAs

can be quickly read on the elevation knob.

Example

17.5 MOA reticle holdover at 625 yards. No wind.

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Windage and Moving Targets

RIFLESCO PE

The EBR-1 MOA reticle is highly effective when used for wind

and moving target leads. Using the reticle for effective windage

and moving target leads will require thorough knowledge of your

weapons system’s ballistic performance under varying conditions and

experience in reading wind strengths and target speeds. As in bullet

drops, it is important for the shooter to learn a particular weapon’s

windage/moving target corrections in MOAs rather than inches.

Always hold the reticle into the wind.

Basic windage correction on center crosshair

When dialing elevation come ups, the center horizontal crosshair will

be used for windage or moving lead corrections.

Example

10 mph wind

Full value wind at 90 degrees

3 MOA reticle windage correction at 400 yards in 10 mph crosswind using
center crosshair. Elevation adjustment already dialed into the riflescope.

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RIFLESCO PE

Basic windage correction using drop line on reticle

When using the reticle for elevation correction rather than dialing,

the MOA marks on the center horizontal crosshair can still be used

to help visually reference windage corrections. Remember to hold the

reticle into the wind.

Example

20 mph wind

Full value wind at 90 degrees

Basic moving lead correction

When estimating moving target leads, the MOA marks on the center

horizontal crosshair can be used. Estimating moving target leads will

require knowing yardage distance, wind speed, moving target speed, and

total bullet flight time (including rifle lock time). Bullet flight times can be

roughly calculated based on fps velocities or a ballistic calculator.

Note: Correctly estimating moving leads is very difficult and requires

considerable practice and knowledge beyond the scope of this manual.

Example

Direction of Movement

8 MOA reticle windage correction at 500 yards in 20 mph crosswind using
12 MOA reticle drop line.

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9.4 MOA reticle correction for a target moving 3 mph at a distance of 800 yards.
No wind. Total bullet time of flight from trigger pull is 1.5 seconds during which
target travels 6.6 feet. Elevation already dialed into turret.

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THE VIP WARRANTY

We build optics based on our commitment to your absolute satisfaction.

That’s why Vortex products are unconditionally guaranteed and we

make this Very Important Promise to you—a Very Important Person.

Rest assured that in the event your Viper PST becomes damaged or

defective, Vortex Optics will repair or replace the

riflescope at no charge to you. Call Vortex Optics

at 800-426-0048 for prompt, professional, and

friendly service.

Vortex Optics

2120 West Greenview Drive

Middleton, WI 53562

[e-mail]

Visit www.vortexoptics.com for more information. Canadian customers

may visit www.vortexcanada.net for customer service information.

Note: The VIP warranty does not cover theft, loss, or deliberate damage

to the product.

Unlimited

Unconditional

Lifetime Warranty

RIFLESCO PE

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