How to Sight in a Rifle Scope

Table of Contents

1. Introduction
2. Preparation and Mounting Fundamentals
3. Phase 1: Bore Sighting Without Tools
4. Phase 2: Utilizing Laser Bore Sighters
5. Phase 3: The 25-Yard Initial Zero
6. Phase 4: Walking it Out to 100 Yards
7. Phase 5: Confirming the Zero
8. Common Mistakes to Avoid
9. Advanced Considerations: The 50/200 Zero
10. Conclusion
11. FAQ

Introduction

There is nothing more frustrating than heading to the range with a new optic and burning through two boxes of match-grade ammunition just trying to get a round on the paper. Whether you are an active-duty operator prepping a new duty rifle or a civilian enthusiast setting up a precision bolt-gun, the ability to efficiently sight in a rifle scope is a fundamental marksmanship skill. At Crate Club, we believe that your gear is only as good as your ability to maintain and calibrate it. Understanding the mechanics of bore sighting, turret adjustments, and grouping will save you time, money, and ammunition. This guide covers the step-by-step process of moving from a fresh mount to a confirmed zero at distance. By following a disciplined procedure, you ensure your rifle performs when the stakes are high.

For a broader overview of the process, read our guide to zeroing a rifle scope. Shooters building a more advanced precision setup can also explore the Major tier for curated tactical and maintenance gear.

Preparation and Mounting Fundamentals

Before you ever chamber a round, your hardware must be squared away. A scope that is improperly mounted will never hold a consistent zero, no matter how much ammunition you throw at it. You must ensure your rings are torqued to the manufacturer’s specifications, usually measured in inch-pounds. Over-tightening can crush the scope tube or bind the internal adjustment tracking, while under-tightening allows the optic to shift under recoil.

We recommend using a leveling system to ensure the reticle is perfectly vertical. A canted reticle means that when you adjust for elevation at long ranges, you are inadvertently adding windage error. Ensure your eye relief—the distance between your eye and the rear lens—is set while in your natural shooting position. Once the optic is physically secure, you are ready to move to the sighting process.

Quick Answer: Sighting in a rifle scope involves aligning the optical center of the scope with the point of impact of the bullet at a specific distance. This is achieved through bore sighting to get on paper, followed by live-fire adjustments using the scope’s elevation and windage turrets.

For additional guidance on scope components and installation, review how to sight in a tactical rifle scope.

Phase 1: Bore Sighting Without Tools

Bore sighting is the process of aligning the center of the barrel (the bore) with the center of the optic. This does not result in a perfect zero, but it ensures your first shot will hit a large target at 25 yards. The most reliable way to do this without specialized tools is the visual method, which works best on bolt-action rifles or AR-platforms where you can remove the upper receiver.

Step 1: Secure the rifle. / Place the rifle or upper receiver in a steady lead sled, sandbags, or a gun vice where it will not move.
Step 2: Remove the bolt. / Pull the bolt carrier group or bolt out so you can look directly through the rear of the receiver and down the barrel.
Step 3: Target acquisition. / Look through the bore and center a high-contrast target (like a black bullseye) at 25 yards within the circle of the barrel.
Step 4: Align the reticle. / Without moving the rifle, look through the scope and use the turrets to move the crosshairs until they rest on the exact same target you see through the bore.
Step 5: Verify. / Double-check that both the bore and the scope are pointing at the same point of aim.

For a deeper explanation of this preliminary alignment, see how to bore sight a scope.

Field Note: Visual bore sighting is often more reliable than cheap laser tools because it relies on the actual geometry of your barrel rather than a potentially misaligned laser insert.

Phase 2: Utilizing Laser Bore Sighters

For semi-automatic rifles where you cannot look through the bore, or for a faster setup, a laser bore sighter is a valuable addition to your range bag. These tools come in two primary forms: chamber inserts that look like a cartridge and muzzle-mounted units that use magnets or arbors.

Chamber-style lasers are specific to the caliber, such as .223 Remington or .308 Winchester. You drop them into the chamber, and they project a laser dot exactly where the barrel is pointing. Muzzle-mounted units, like those from Wheeler or SiteLite, are universal. We often include high-quality maintenance and calibration tools in our Major tier crates because we know that precision discovery is a major part of the tactical hobby.

You can compare available range and calibration gear in the Gear Shop before your next range session.

While lasers are convenient, remember that they project a straight line, whereas a bullet follows a ballistic arc. A laser will get you on the paper, but it is never a substitute for live-fire confirmation.

For more background on the equipment and process, read how a bore sight works.

Phase 3: The 25-Yard Initial Zero

Once bore-sighted, move to a live-fire range. Start at 25 yards. At this close distance, it is nearly impossible to miss the entire target board if you bore-sighted correctly. Using a 25-yard target allows you to see exactly how the mechanical offset (the height of the scope above the bore) affects your point of impact.

Fire a three-round group while maintaining a consistent point of aim at the center of the target. Do not chase the first shot; fire all three rounds to see where the rifle is naturally grouping. If your group is two inches low and one inch right, you need to adjust your turrets.

Understanding MOA and Mil Adjustments

Most scopes adjust in Minutes of Angle (MOA) or Milliradians (Mils).

• MOA: One MOA is roughly 1 inch at 100 yards. At 25 yards, one MOA is only 1/4 of an inch. If your scope has 1/4 MOA clicks, it takes 16 clicks to move the point of impact one inch at 25 yards.
• Mils: One Mil is 3.6 inches at 100 yards. At 25 yards, one Mil is 0.9 inches.

Read the markings on your turrets. If the turret says "UP," turning it in that direction moves the bullet's point of impact up. Adjust your windage and elevation until your three-round groups are hitting the bullseye at 25 yards.

For related precision fundamentals, continue with how to aim with a sniper scope.

Phase 4: Walking it Out to 100 Yards

Once you are dead-on at 25 yards, move the target to 100 yards. This is the standard zero distance for most tactical and hunting rifles. Because the bullet is traveling further, any slight misalignment at 25 yards will be magnified.

Fire another three-round group at the 100-yard target. At this distance, the math for your turrets becomes much simpler. If you are using a 1/4 MOA scope and your group is 2 inches low, you need to click "UP" 8 times (2 inches / 0.25 inches per click). If you are 3 inches left, you need to click "RIGHT" 12 times.

Key Takeaway: Always adjust the scope based on the center of a group, not a single "flyer" or outlier shot. Consistency in your shooting form is required to achieve a true zero.

If you want to compare the process for a common precision caliber, see how to zero a .308 rifle.

Phase 5: Confirming the Zero

After making your adjustments at 100 yards, fire a final five-round group. This is your "confirmation group." If the group is centered on the bullseye, you have successfully sighted in your rifle.

At this stage, many operators choose to "slip the scales" or "zero the turrets." Most quality optics allow you to loosen a small set screw on the turret caps and rotate them so the "0" mark aligns with the indicator line without changing the internal settings. This allows you to make field adjustments for wind or elevation and always return to your original 100-yard zero quickly.

For those looking for premium optics and mounting hardware, our Gear Shop features vetted brands like Sig Sauer and Bushnell that are designed to hold zero under harsh field conditions.

You can also review past Major Supply Drop contents for examples of the maintenance and field equipment included in higher-level crates.

Common Mistakes to Avoid

Even experienced shooters can run into issues when sighting in. If your groups are sporadic and won't tighten up, check these common failure points:

• Loose Mounts: This is the number one cause of zero drift. Use a witness mark (a small line of paint or marker) across the screw and the ring to see if they are backing out under recoil.
• Parallax Error: If your scope has a parallax adjustment (often a side knob), ensure the target is in focus and the reticle does not shift when you move your head slightly.
• Barrel Heat: A hot barrel will often cause "stringing," where the shots start to climb or move in a line as the metal expands. Give the rifle time to cool between groups.
• Poor Rest: Do not sight in a rifle while standing or sitting unsupported. Use a bench, sandbags, or a bipod to remove human error from the equation.

For a related look at equipment care and field readiness, explore another past Major crate breakdown.

Bottom line: A successful zero requires a solid mechanical foundation, a disciplined bore-sighting process, and a clear understanding of your optic's adjustment values.

Advanced Considerations: The 50/200 Zero

For many tactical shooters using an AR-15 with a 5.56 NATO round, the 50/200 yard zero is a popular choice. Because of the bullet’s trajectory, a rifle sighted in at 50 yards will often be back on target at roughly 200 yards. This creates a very flat "point blank range" where the bullet stays within a few inches of the line of sight from the muzzle out to 250 yards. If you choose this method, follow the same steps described above but perform your final confirmation at 50 yards instead of 100.

Regardless of the zero distance you choose, the process remains the same. Consistency is the goal. We have found that the best way to maintain these skills is through regular range sessions and having the right tools on hand before you leave the house. Our Captain tier, our most popular subscription, frequently includes the type of range essentials and tactical gear that make these sessions more productive.

See what comes inside the Captain crate to explore the gear level associated with this subscription.

Conclusion

Sighting in a rifle scope is a blend of mechanical preparation and mathematical precision. By starting with a proper mount, performing a visual bore sight, and systematically moving from 25 to 100 yards, you can achieve a professional-grade zero with minimal waste. This process transforms a rifle from a collection of parts into a reliable tool that you can trust in a defensive or survival situation. Crate Club is dedicated to providing the Spec Ops-vetted gear and knowledge necessary to keep your kit in peak condition. Once your rifle is zeroed, the next step is getting out to the range and training until that zero becomes an extension of your intent. To get the best tactical and survival gear delivered to your door, choose your Crate Club subscription tier and join a community that takes preparedness seriously.

FAQ

What is the difference between bore sighting and zeroing?

Bore sighting is a preliminary alignment that ensures the scope is looking in the same general direction as the barrel, intended to get your first shots on a large target. Zeroing is the live-fire process of fine-tuning the scope's turrets so that the point of aim exactly matches the point of impact at a specific distance.

For more detail, read what bore sighting is used for.

Can I sight in a rifle at 25 yards for 100 yards?

Yes, you can perform an initial zero at 25 yards, but you must confirm it at 100 yards. Because of the bullet's trajectory and the height of the scope above the bore, a perfect 25-yard zero will often hit several inches high or low at 100 yards depending on the caliber and velocity.

Why does my point of impact change every time I go to the range?

This is known as "zero shift" and is usually caused by loose mounting hardware, extreme temperature changes, or barrel harmonics. Ensure your scope rings are torqued correctly and check for any movement in the stock or the rail system before assuming the optic itself is failing.

Should I use a red or green laser bore sighter?

Green lasers are generally superior for outdoor use because the human eye is more sensitive to green light, making it visible even in bright daylight. Red lasers are more affordable and work well for indoor ranges or low-light conditions, but they can be difficult to see on a target at 50 or 100 yards in the sun.