Long Range Shooting – How to Zero Your Scope

Ready to take your perfect long range shot? Let’s take the first step together: zeroing the rifle scope.

This step is essential, and must be carried out with extreme accuracy, since the results of your shooting will depend on your zero and the data you collect during the zeroing process.

Zeroing the rifle scope is the process of adjusting your sights to be able to hit dead center at where you are aiming at a given distance. The distance at which you zero depends on the kind of shooting activity that you are going to do, on the calibre that you are using, on the scope adjustment unit of measurement, and on personal preferences.

Personally, I always zero high power rifles at 100m or 100yds. Why would I zero at 100yds if I plan on shooting five to ten times that distance? The shorter the distance, the less the external variables will affect the POI. If you wanted to zero at a further distance, let’s say 300yds for example, the POI would be affected by all the external variables in such a way that the zero would not be true anymore when one or more of those variables change. That means that every time you shoot in different conditions, you have to calculate the zero shift, adding complexity to the already complex process of ballistic calculation.

In theory, zero ranges shorter than 100yds (or 100m) would be even better; however, at shorter ranges the bullet has not “gone to sleep” yet, because of the dynamic stability issues, so you’d have an excessive dispersion, which would make you unable to zero with the necessary degree of accuracy. Remember, the shorter the zero range, the higher the zero accuracy must be.

Prior to starting the zeroing process, you need to properly set up your scope. The first thing to do is to adjust the eyepiece. The eyepiece, that is the rear lens of the scope, can be rotated to focus your eye on the reticle. That is its only job and you can’t use it to focus on the target or to adjust parallax.

Focusing the reticle is essential because otherwise you may find yourself with the parallax perfectly tuned, the target image perfectly focused, but with the reticle out of focus. A crisp and sharp reticle is essential in long range shooting. You’ll also want to avoid to shifting your eye focus between the reticle and target because this causes unnecessary eyestrain.

You need to regulate the eyepiece the first time you use the scope, and every time you use someone else’s rifle/scope especially if you, or the rifle’s owner, wear glasses. If the eyepiece doesn’t have a regulation lock, it’s good practice to mark your setting with a permanent marker (only if the scope is yours, of course), or to control reticle focus every time you use it.

To focus the reticle: turn the eyepiece counter-clockwise until it stops, or until the stop mark. Then, point the scope (without looking through it) at the sky. At this point, you can look through the scope, and you’ll see the reticle appears fuzzy because it’s way out of focus. Now you can start to rotate the eyepiece clockwise, 1/2 or 1/4 turn at time, depending on how wide the regulation is, looking out of the scope and then in again every step to prevent your eye from adjusting the focus on its own. When the reticle appears fully sharp and crisp, you’re good to go.

Once you have properly set your eyepiece, if your scope allows you to do that you need to adjust parallax, as explained in this article, zeroing parallax.

Now you’re ready to start the zeroing process. On the next article I’ll talk about how to do that with a newly installed scope. Stay tuned!