Basic Guide To Sighting In A Red Dot — Andre' Dall-au

Red dot sights are among the most versatile optics available for gun owners. Their design allows for rapid target acquisition, an unobstructed correct sight picture, and ease of use. These aforementioned benefits make them popular for self-defense, shooting sports, and general marksmanship. However, just like traditional rifle scopes, red dot sights must be properly zeroed to ensure accuracy. If you spent any time at the range, you've seen fellow shooters struggling to Zero their optic. Truth be told, all of us may have struggled at one time or another. The Basic Guide To Sighting In A Red Dot will give you the solution. Works on rifle scopes too. As basic as it is, it is fundamental to becoming a precision shooter.

Does Zeroing In Your Red Dot Optic Make You Nervous?

If you’re new to red dot sights, the process of sighting in—or zeroing—your optic may seem intimidating. Fortunately, with the right knowledge, you can efficiently zero your red dot without wasting time or ammunition. In this guide, we’ll walk you through everything you need to know about zeroing a red dot sight, from bore sighting to live fire adjustments, ensuring that your optic is dialed in for maximum accuracy.

Understanding Red Dot Sights

A red dot sight is a non-magnified optic that projects an illuminated dot onto a lens, aligning with your target. Because these sights use a single focal plane, shooters can keep both eyes open, enhancing situational awareness and improving accuracy. The point of impact should align with the dot, but this requires proper zeroing to ensure precision. As a general rule, reflex sights fall into this category. Although reflex sights and red dots are not used for long range, their effective range can be increased with the use of a magnifier. More about that later.

Red dot sights and reflex sights come in various sizes and configurations. Some feature small dots, ideal for precise shooting, while others have larger dots suited for fast target acquisition in close-quarters engagements. Some models offer adjustable brightness settings, allowing shooters to adapt to different lighting conditions. Understanding these features will help you choose the right optic for your needs.

Why Bore Sighting Matters 

Before firing live rounds, you can save time and ammo by bore sighting. Bore sighting helps align your optic with the barrel, ensuring that your initial shots are closer to the target. There are two main methods to bore sight your red dot sight: using a laser bore sight or manually bore sighting.

Bore sighting is especially useful for those mounting a red dot on a new firearm or changing optics. Without bore sighting, your shots may land far from the target, requiring more adjustments and ammunition to zero properly. Taking the time to bore sight first simplifies the process and improves efficiency.

How to Bore Sight Without a Laser

Set Up Your Rifle Securely: Your firearm should be stable, ideally mounted in a gun vise or resting on a bench with a bipod or sandbags. Position a Target: Place a target at 25 yards for initial bore sighting. Align the Barrel: If using a bolt-action rifle, remove the bolt and look through the barrel to center the bore on the bullseye. For AR-style rifles, remove the bolt carrier group to achieve the same effect. Adjust the Red Dot: Without moving the firearm, adjust your red dot sight’s windage (left/right) and elevation (up/down) so the reticle aligns with the bullseye.

How to Bore Sight with a Laser Bore Sight

Insert the Laser Bore Sight: Depending on the model, it will fit into the chamber or the muzzle of your firearm. Align the Reticle: The laser will project a dot onto your target. Adjust the red dot sight so it aligns with the laser’s position. Remove the laser bore sight: After alignment, remove the laser before firing live rounds. Using a laser bore sight typically results in slightly more precise initial alignment. However, if using a bore sighting tool doesn't work for you, the manual method is just as effective. The Best Laser Bore Sights In 2025 is a good place to start to find a Bore-Sighter if you don't have one.

Backyard laser bore sight projected on a bicycle reflector. Photo Credit: Andre' Dall'au

Live Fire At The Range For Fine Tuning

Once bore sighted, fine-tuning your red dot sight requires live fire. Follow these steps to complete the zeroing process:

Set Up a Target at Your Desired Distance: For pistols: A 25-yard zero is practical for self-defense and general shooting.

For rifles: A 50-yard zero is ideal for most applications.

Fire a Grouping Fire three to five rounds while maintaining a consistent point of aim. Observe the group’s placement relative to your intended target.

Calculate and Adjust Measure how far your group is from the bullseye. Use the Minute of Angle (MOA) formula to determine the necessary adjustments:

Adjustment in MOA = (Distance from bullseye in inches) / (Shooting distance in yards / 100) Example: If your shots are 0.25” low and 0.5” left at 25 yards, adjust your red dot 1 MOA up and 2 MOA right.

Adjust the Red Dot Sight Depending on your optic, adjust windage and elevation using the sight’s turrets or digital buttons.

Confirm the Zero Fire another three to five-round grouping to verify accuracy. Repeat adjustments as necessary until the point of aim matches the point of impact. Zeroing should be a methodical process. Rushing through it can result in inconsistent performance, so take your time to ensure your optic is properly dialed in.

MOA and Why It’s Important

MOA (Minute of Angle) is a standard measurement for sight adjustments. One MOA equals 1 inch at 100 yards. This means: 1 MOA = 0.5 inches at 50 yards1 MOA = 0.25 inches at 25 yards. MOA helps shooters make precise adjustments to their optics. Some red dot sights adjust in ½ MOA or 1 MOA increments, meaning that each click or button press moves the point of impact by that amount. Knowing your sight’s adjustment values will help you make more accurate corrections.

How Often Should You Bore Sight or Zero Your Red Dot? 

You don’t need to bore sight every time you shoot, but you should re-zero your optic if you: Change your red dot sight or rifle. Switch to a different ammunition type. Experience a significant impact to your firearm that may shift the zero. Regularly checking your zero ensures consistent performance, especially if using your firearm for self-defense or competitive shooting.

Final Thoughts On Basic Guide To Sighting In A Red Dot

Zeroing your red dot sight or variable optic is essential for accuracy and confidence in your shooting. Whether you use a laser bore sight or the traditional method, taking the time to align your optic properly will improve your shooting experience and save ammunition.

If you’re in the market for a high-quality red dot sight, check out the Mepro Tru-Vision™ SR — built to military standards with Selectable 2/65 MOA Speed Ring or 2 MOA dot reticle options.

Explore the full range of Meprolight® dot sights at meprolight.com and find the optic that best suits your needs.

By following these steps, you’ll gain confidence in sighting in your red dot, ensuring that every shot counts. Whether you’re a beginner or an experienced shooter, mastering the art of zeroing is a skill that enhances both precision and performance. Shooting red dots that are accurate is fun. It may seem like work at first, but after that, it becomes second nature.

Take the shot! 

A zeroed rifle gives you the confidence you need to Make The Shot.