How to Adjust Your Rifle Scope?

If you're new to scopes and unsure how to adjust the turret or calculate the necessary adjustments, this article will guide you step-by-step using plain language. We’ll explain everything you need to know, including: what MOA is, what MOA means on the reticle, and how MOA translates to specific distances, how to convert the unit, etc. 

The very first step is to understand the bullet trajectory. There are three main types of trajectories: flat, arched, and curved. A flat trajectory occurs only at very short distances. A curved trajectory is typically caused by external factors like wind, altitude, etc.

However, the most common is the arched trajectory, which is the focus of this article. In an arched trajectory, the bullet rises initially and then falls due to gravity. Fortunately, you don’t need to dive deep into physics to achieve accurate shooting.

Many factors influence bullet trajectory, including weather conditions such as temperature, humidity, and wind, the bullet's characteristics like weight, shape, and aerodynamic design, and the angle at which you shoot.

For turret adjustment, you just need to know the arched one to understand further calculation.

What is bullet drop? and Why there is bullet drop? 

Due to the recoil, the bullet muzzle velocity, and the gravity, the bullet will move like an arc. The line will go up then go down due to the gravity.

The arce become steeper as the gravity increase when the velocity decrease, as the bullet flys. 

To keep it simple, with the same ammunication, if you zero your rifle at 200 yards, the bullet's point of impact at 50 yards might be similar to its impact at 300 yards. The bullet's trajectory peaks around 95 yards, so at 100 yards, it will still hit higher than at 300 yards. The diagrams below should make this easier to visualize.

Therefore, after zeroing your scope at a specific distance, you’ll need to adjust the turret to ensure accuracy at other distances. This requires knowing how many clicks to make and whether to turn the turret clockwise or counterclockwise. These adjustments compensate for bullet drop, ensuring your point of impact matches your point of aim at varying distances.

Bullet drop refers to the difference between where you aim (the point of aim) and where the bullet actually lands (the point of impact). To ensure precision, you need to compensate for this drop by adjusting your turret. By calculating the bullet drop and making the necessary adjustments, you can align the point of impact exactly with your point of aim, ensuring accurate shooting at any distance.

What is the Adjustment System?

There are two common adjustment units for scopes, MOA (Minute of Angle) and MIL (Milliradian). Both are angular measurements, meaning the amount of vertical compensation for 1 MOA or 1 MIL varies depending on the horizontal distance to the target. In other words, the farther the target, the greater the physical distance represented by 1 MOA or 1 MIL.

For shooters, remember these key points: 

MIL System: 1/10 MIL = 1 cm at 100 meters. Most MIL scopes adjust in 1/10 MIL clicks.

MOA System: 1 MOA = 1 inch at 100 yards. Common click values are 1/4 MOA or 1/8 MOA.

The MIL system is straightforward and easy to use. At 100 meters, 1/10 MIL equals 1 cm. Similarly, at 1000 meters, 1/10 MIL equals 10 cm. 

For people who are only familar with either one of the unit, you may need to covert the unit according to your rifle scope.

1 yard = 0.9144 m 

1 inch = 2.54 cm 

It is helpful to understand the click value before learning how to adjust your scope. If you wish to learn more, read our other blog post. 

How to Use Ballistic Table?

Next, you’ll need to learn how to read a ballistic table. Most bullet boxes include a ballistic table on the back, which shows the bullet’s trajectory at various shooting distances.

When the bullet drop / trajectory is listed as 0 in the ballistic table, it indicates the distance at which you should zero your scope. 

For example, a .338 ballistic table presents that at 200 yards, the bullet trajectory is 0. That means you should zero at 200 yards. Zeroing means aligning your point of aim with the point of impact at that specific distance.

After zeroing, if you change the shooting distance, you’ll need to adjust the turret to compensate for the drop, as indicated in the ballistic table. 

According to the table, if you change the shooting distance to 100 yards, you will need to adjust the turret to compensate for 1.8 inch drop. That means you need to move your point of impact downward by 1.8 inch at 100 yards. 

If you change the shooting distance to 300 yards, you will need to adjust the turret to compensate for -7.8 Inch. That means you need to move your point of impact upward by 7.8 Inch at 300 yards. 

How Many Clicks You Need to Adjust?

Next, you’ll need to calculate how many clicks are required for the elevation adjustment based on your scope’s click value.

For instance, according to the ballistic table, you need to compensate 1.8 inch and the click value of the scope is 1/4 MOA.

Times of the Clicks = Bullet Drop Compensation / Click Value

Times of the click = 1.8 Inch / 1/4 MOA (Inch) = 7.2 ≈ 7

Then you will need to adjust the turret 7 times.

As we mentioned before, postive number means that the point of impact is above the point of aim. That means you need to move the point downward. You will need to adjust the turret clockwise. 

Therefore, you should clockwisely adjust the turret based on your zero point 7 times. 

You may notice that as the distance increases, the values become negative. That means the point of impact is lower than the point of aim, so you need to move the point of impact up. To do this, adjust the turret counterclockwise. 

More Practices!

If you are using .338 bullet and your target is at 400 yards. How to adjust your scope with 1/4MOA click value?

Step one: According to the ballistic table, the bullet drop compensation is -48.2 at 400 yards. 

Step two: Times of Click Value = Bullet Drop Compensation / Click Value = -48.2 / 1/4 MOA = -192.8 ≈ 193

Step three: Adjust the scope 193 times. But nobody gonna count 193 times. 

Simplified Step three: Adjust 48MOA based on your zero point directly. Then 0.2 / 1/4 MOA = 0.8 ≈ 1, with one more click.

If you are using .338 bullet and your target is at 400 yards. How to adjust your scope with 1/10MIL click value?

Step one: If the ballistic table is with Inch, yard unit and the click value of the scope is MIL unit, you will need to know how to convert the unit.

1/10 MIL = 1 cm at 100 m

1 MIL = 3.43 MOA

Step two: -48.2 MOA / 3.43 = 14.05 MIL

Step three: Adjust the turret 14 MIL (with one more clicks of 1/10MIL, if you want to), based on your zero point. 

Here is more examples with .308 ballistic table.

If you are using .308 bullet and your target is at 100 yards. How to adjust your scope with 1/8MOA click value?

Step one: Check the ballistic table, at 100 yard, the bullet drop 2.1 inch, 2.1 MOA

Step two: 2.1 MOA / 1/8 MOA = 16.8 ≈ 17

Step three: Adjust turret 17 clicks based on your zero point or 2MOA and one more click of 1/8 MOA. 

If you are using .223 bullet and your target is at 200 yards. How to adjust your scope with 1/8MOA click value?

Step one: Check the ballistic table, at 200 yard, the bullet drop 3.3 inch, 3.3 MOA.

Step two: 3.3 MOA / 1/8 MOA = 26.4 ≈ 26

Step three: Adjust 3MOA (24 clicks), and then 2 more clicks.

Conclusion

In real situation, you will need to consider many factors, including temperature, air pressure, air humidity, bullet weight, muzzle velocity, etc.

You can use our recent blog posts, what is the MOA, how to estimate the hunting distance, to start to practice your shooting technique, during plinking at home.

After you understand all of these, the calculation became quite simple! But in real situation, things become complicated. You will need to take tons of shot to practice and gain experience to take a precise shot, with the consideration of weather, altitude, etc.