How to properly adjust your rifle scope?

Adjusting a rifle optic is an essential step in the life of a sports shooter or hunter, knowing how to do it yourself is a step in itself in the evolution of weapons skills. However, there are a few tips that can take this practice to the state of the art.

In this article, we offer to guide you step by step in adjusting your optics.

The few prerequisites: 

We assume that your scope has already been properly mounted: Leveling, correct eye relief, etc. This is to condense the size of our writing. A scope is said to be adjusted when the bullets hit the point targeted by the reticle. The reticle can be moved by using the turrets to match the pointing of the reticle to the location of the impacts.

Step 1: The simbleautage

It sometimes happens that when mounting the scope, the latter is not on its optical center, resulting in your first bullet being off target even at short distances, this situation can be particularly dangerous...

This is why we recommend that you carry out a so-called “simbleautage” step beforehand for the first shot.

The method for making a simbleautage

You will need to place a large target (C50 for example) at a relatively short distance of 25 meters or 50 meters (100 meters for those who are used to it). You will then need to place your weapon on a stable support (tripod / bipod / bag / ...), You can then remove the slide in order to be able to look through the axis of the barrel and point it towards your target.

Holding the weapon perfectly still, now look through your scope. The reticle should be centered on your target at the same time as your barrel is pointing at it.

If your gun and scope are not pointing at the target at the same time, then you will need to click on the turrets of your scope.

The top turret allows you to raise or lower the reticle, the direction of rotation is generally noted by the mention “U” or “Up” which means to raise in English, so in this direction of rotation the point of impact will rise in target (so my reticle descends)

The side turret allows the reticle to be moved laterally from left to right or from right to left depending on the direction of rotation of the turrets. As on the elevation turret, an “R” mark is generally present meaning “Right” in English indicating the direction to send the impact to the right.

When the reticle and the axis of your gun are pointing at the same time at the center of your target, you can reset your slide and fire your first bullet on target!

TIP: Some weapons do not allow the slide to be removed (AR-15, lever-action rifles under guard, etc.). For these weapons, we advise you to fire your first bullet at a reduced distance between 10 and 20 meters to guarantee a bullet on target.

Step 2: Bring the impacts closer to the center

This step consists of bringing your impacts closer to the center of the target. There are several possible methods for this

Method 1: The universal method of converting to clicks

Our first technique is to measure the location of our first impact in relation to the target point (center of the target). It is measured as a difference in height and width. Insert IMAGE #3

Once your measurements are taken You will then need to convert the measurements taken in order to pass them from centimeters to units of angles, in fact all scopes work either in MOA (Minute Of Angle) or in Mil (Milliradian) which are two units of angles (one imperial which comes to us from across the Atlantic, one metric). On your scope will necessarily be written a subdivision of one of these units of angles (⅛ MOA, ¼ MOA, 0.1 mil)

This element allows you to know the value of the correction of each click.

You will only have to convert these measurements using the attached conversion table.

Let's take an example: I measure a height difference in target of 14cm (140mm) at a distance of 100 meters. If my scope is in ¼ MOA, the value of a click at the distance is 7.3mm. All I have to do is divide the difference measured in target (in mm) by the value of a click -> 140/7.3= 19 clicks. As I cannot do half clicks, I would do 19 clicks.

In our case:

Our target is at 100 meters, our scope is graduated in 0.1 mil at this distance each click is 1cm, we will therefore have to go down 14 clicks and send to the left 7 clicks.

-> Advantage: Low cartridge consumption, does not require a perfectly stable support (vice), allows you to work on some angle conversion calculations, maths never hurts!

-> Disadvantage: You have to go back and forth, have a tape measure and a calculator

Method 2: Using a First Focal Plane “FFP” Reticle

This method involves measuring in the reticle of your scope the difference in height and width between the point you are aiming at and your first hit.

How do you know if your reticle is at the 1st focal plane?

The reticle “magnifies” with the zoom, your graduations always point to the least points in space whatever the zoom value of your scope, allowing you to measure angles or distance whatever the value of your zoom.

Using your reticle, you measure directly in units of angles, no calculations to do!

You will need to point your reticle at your target point and measure the number of graduations vertically and horizontally to find your first impact.

Once the number of graduations is noted, you will need to refer to the reticle manual to find out the value of a graduation (even if most reticles are graduated in 0.2 mil these days). Of course, once the correction is measured, all you have to do is transfer it to your turrets to make the adjustment, paying attention of course to the direction of rotation of the turrets.

In our example, here we measure 7 graduations vertically, 3.5 graduations horizontally. As the reticle of our scope is graduated in 0.2 mil (value of 2 clicks)

7 graduations = 7x0.2 = 1.4 mil = 14 vertical clicks

3.5 graduations = 3.5x2 = 0.7 mil = 7 clicks to the left.

-> Advantage: No need to move from your seat, allows you to take control of the scope reticle, does not require extremely stable support.

-> Disadvantage: Requires a telescope at the first focal plane…

You can now, whatever method you used, shoot your second bullet, which should be very close to the center…

Step 3: Finalize with a precise grouping

Now we're going to switch to a smaller target! Because the smaller the target, the better the shooter's aim will be, the center circle of a C50 target is too big to aim with the best possible accuracy.

An improved version can be downloaded here: HERE

We use some special visuals for our zeroing, a cross with a circle at the bottom. If your reticle has a central dot, you can center it with the target circle. If your reticle has a solid cross, you can superimpose it with the reticle cross.

It is now time to perform a grouping of at least 10 shots in order to center your scope on the center of a large group.

Example of using this target:

We aim at the bottom circle and make this grouping of 19 shots, which arrives higher than our aiming point.

To measure the difference in elevation and lateral, using a caliper is the simplest and quickest method.

There are also apps that scan your target to give you your grouping correction relative to the target point! (Hornady 4DOF for example)

Here the application tells us that our grouping of a respectable size of 2.56 cm is located:

- 1.68 cm above our target point (Elevation Offset)

- 0.11 cm to the right of the target point (Windage offset)

Since our target is at 100 meters and our scope is graduated in 0.1 mil (1 click = 1 cm at 100 meters), all that remains is to click:

- Go down 2 clicks, our grouping will be 0.32 cm low (1.68cm - 2 cm = - 0.32cm), but we can't do better!

- Regarding left right, No need to click, we are at 0.11 cm (10% of the value of a click)

And here is our perfectly done adjustment!

If you are not confident, you can always regroup to make sure you did not make a mistake (rotation direction or conversion)

Now that you have a reliable hit point aim point, all you have to do is zero your turrets, this step consists of placing the origin of the turrets on our setting, because it is unlikely that you will have landed on the value “0” once set!

How to zero your scope?

The first step is to “disengage” your turret from its axis.

Depending on the model of your scope, this operation differs, we invite you to refer to the instructions for your optic. In our case, we need to unscrew three small hexagonal screws placed on the periphery of the turret. Some scopes have a central screw to unscrew (be careful to hold the turret when unscrewing to avoid clicks when loosening the turret)

Now that your turret is “free” and when you turn it you no longer hear “clicks”, you just have to align the turret on zero and tighten the clamping screw(s) according to your model.

Of course, this operation must be done for both turrets.

We advise you to group at 100 meters to ensure that no clicks have interfered with your adjustment when disengaging the turret, this happens more often than you think!

And there you have it, you now have a perfectly adjusted and zeroed scope!