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  • Post last modified:August 14, 2023

In this scope guide, we are going to talk about a very important topic that has to do with accuracy with your aim.

Scope parallax is when the field of view and the reticle are not simultaneously in focus, which causes a problem with accuracy when doing long-range shooting.

So do you need side parallax adjustment on your rifle scope?

After you read this guide, you will have a better understanding of how it works and how it can increase the accuracy of the aim.

Let's find out.

Do You Need Side Parallax Adjustment On A Rifle Scope?

The use of side parallax adjustment on a rifle scope is important for accurate aim on a target at long distance, and it's needed for long-range precision shooting.

Problems Dealing With Scope Parallax

  • Target and reticle are not in the same plane, separated by space inside the scope
  • Eyes not perfectly centered behind the scope will cause the reticle to shift.
  • Requires perfect cheek position, and sometimes it's not always possible due to various shooting positions
  • The reticle is perfectly aligned with the target, but when moving the head around throws it off

The biggest problem affects accuracy – The parallax is detectable when you move your head or eye around while looking through the scope and the reticle appears to move or swim around the object you at which you are aiming.

Moves as much as just 2″, that will be about a 2″ error in addition to other dispersion of the rifle is.

Even if you have a 0.5 MOA rifle, that parallax will turn that rifle into a 2.5 MOA rifle due to that small error downrange.

How Does Parallax Look Like

how does scope parallax look like inside a rifle scope
Inside the scope looks like
rifle scope parallax illustration 1
What the shooter sees

This is true for reflex red dot and magnified rifle scopes.

In order to ensure that the point of aim is the point of impact, the shooter needs to adjust the parallax on the scope to ensure no parallax shift when the head positions slightly move.

How Does Zero Parallax Look Like (What We Want)

After adjusting the parallax, it looks like this:

Zero parallax rifle scope

How Does Parallax Adjustment Work On A Rifle Scope?

Most variable zoom rifle scopes that feature parallax adjustment is located on the side of the scope by the elevation and windage turrets.

Once you know the distance to the target you can adjust the parallax to align the reticle plane to the target plane.

It will look something like this:

Rifle scope side parallax adjustment knob

What Type Of Scopes Have Parallax Adjustment Knob Built In?

Most high-quality scopes built for long range shooting will have side parallax adjustment knob.

Brands like Leupold, Vortex, Nightforce, Burris and many more have them.

If you're shooting long range with the wrong scope or getting started, please check out our best long-range rifle scope under $1000 guide to get started, and yes those rifle scopes will have a parallax adjustment knob built in to help you solve the parallax issue to be more accurate.