How to Sight In a Scope: A Step-by-Step Guide for Precision Shooters

A rifle is only as accurate as the relationship between where you’re aiming and where the round actually lands. Get that relationship dialed in, and a good scope turns you into a precise, confident shooter. Skip it, and even the finest optic on the market will send rounds wandering off target.

That process — aligning your scope’s point of aim with your rifle’s point of impact at a set distance — is called sighting in, or zeroing. It sounds like a dark art the first time you do it, but it’s a repeatable procedure that any shooter can learn. This guide walks you through it step by step, from the angular math you need to understand your turrets to the final confirmation group at 100 yards.

What “Sighting In” a Scope Actually Means

Every scope has a point of aim (POA) — the spot your reticle sits on — and every rifle has a point of impact (POI), where the bullet lands. Sighting in is simply the act of making those two line up at a chosen distance.

Here’s the catch: a bullet doesn’t travel in a straight line. Gravity pulls it into a curved trajectory the instant it leaves the muzzle. Your line of sight through the scope, on the other hand, is dead straight. Those two paths only intersect at specific points. When you zero at 100 yards, you’re adjusting the reticle so the bullet’s arc crosses your line of sight right at that 100-yard mark. Aim farther out and the round drops below your crosshair; you’ll need to account for that bullet drop with holdover or by dialing your turret.

A well-established zero gives you consistent groupings, faster target acquisition, and the confidence to know your rifle is doing exactly what you tell it to.

Understand Your Turrets: MOA and MRAD

Before you touch an adjustment dial, you need to know what “language” your scope speaks. Stop thinking in inches and start thinking in angles — because a linear measurement like “two inches low” is meaningless without also knowing the distance to the target.

There are two angular systems you’ll encounter:

• Minute of Angle (MOA): A minute of angle is 1/60th of a degree. In practical terms, 1 MOA equals roughly 1.047 inches at 100 yards — close enough that shooters just round it to “one inch at 100 yards.” Most MOA scopes adjust in 1/4 MOA increments, so a single click moves your point of impact about a quarter-inch at 100 yards. You’ll also see 1/3 MOA, 1/2 MOA, and 1 MOA turrets.
• Milliradian (MRAD or “mils”): A milliradian is 1/1000th of a radian. One MRAD covers about 3.6 inches at 100 yards, and most MRAD scopes adjust in 0.1 MRAD clicks — roughly 0.36 inches per click at 100 yards. Mils shine when you work in the metric system: at 100 meters, one MRAD is exactly 10 centimeters, which keeps the drop and ranging math clean.

Neither system is “better.” Precision and long-range shooters often prefer MRAD, while many red dots and prismatic optics use MOA. What matters is that you know which one your scope uses, because it determines how you’ll read your offset and count your clicks. Check the turret caps — they’ll tell you the click value.

Height Over Bore: Why Close Targets Print Low

Your scope sits above your barrel — typically 1.5 to 2 inches higher on a modern rifle. That vertical gap between your line of sight and the bore axis is called height over bore, and it explains something that trips up a lot of new shooters.

At very close range, the bullet hasn’t had time to rise up to your line of sight yet. So at 25 yards, your point of impact will usually land an inch or two below your point of aim — not because your zero is wrong, but because of that offset. At your true zero distance, POA and POI meet. Beyond it, gravity takes over and the round falls away. Keep this in mind so you don’t chase a “problem” that’s just physics doing its job.

What You Need Before You Start

Sighting in goes smoothly when you set yourself up right:

• A properly mounted scope: Your rings and bases must match your rifle’s rail — usually a Picatinny or Weaver system — and every screw needs to be torqued to spec. Loose mounting hardware is the single most common reason a rifle won’t hold zero, so don’t rush this part.
• An extremely stable platform: A solid bench, a bipod, a rifle rest, or a set of shooting bags. The goal is to remove your body’s wobble from the equation entirely. If you want to build a foundation of solid fundamentals first, our shooting range tips cover the positional and trigger basics that make every zero cleaner.
• One consistent load: This is critical: a zero is only valid for one specific cartridge under one set of conditions. Different bullet weights and velocities follow different trajectories, so pick the ammunition you’ll actually shoot and stick with it.
• A good target: A high-contrast grid target designed for zeroing makes reading your offset almost effortless — each square corresponds to a known MOA or MRAD value.

How to Sight In a Scope, Step by Step

1. Set Your Eye Relief and Check for Cant

Mount up, get behind the rifle in your shooting position, and slide the scope forward or back until you see a full, clear image with no dark shadow around the edges. This is your eye relief — set it so the scope never contacts your brow under recoil (a painful mistake known as “scope bite”). If your scope has an adjustable diopter, turn it until the reticle looks crisp. Finally, make sure the reticle is level and the rifle isn’t canted to one side.

2. Choose Your Zero Distance

Your ideal zero depends on how you’ll use the rifle and what you’re shooting at. 100 yards is the standard for most precision and recreational shooters, and it’s the distance almost every ammunition manufacturer bases its ballistic data on. Hunters sometimes prefer a point-blank zero that keeps the round within a useful margin of the aiming point across a range of distances. Whatever you choose, decide before you start — and a free ballistic calculator can help you preview your trajectory and drop for your specific load.

3. Build a Stable Position

Settle the rifle onto your rest or bags and get as steady as possible. The less your natural movement influences the shot, the more your groups reflect the rifle’s true zero rather than your wobble. Whenever practical, zero from a position close to how you’ll actually shoot — a zero can shift slightly between the bench and prone.

4. Bore Sight to Get On Paper

Bore sighting is a shortcut to get your first rounds on the target without wasting ammo. On a bolt gun, remove the bolt and look straight down the bore at the bullseye. On an AR-pattern rifle, separate the upper from the lower and pull the bolt carrier so you have a clear view down the barrel. Center the target in the bore, then — without moving the rifle — adjust your windage and elevation knobs until the reticle sits on that same spot. A laser bore sighter that drops into the chamber or muzzle does the same job. Bore sighting is rarely perfect, but it gets you close enough to start firing.

5. Fire a Group and Read Your Offset

Aim at the center of the target and fire a group — three shots at minimum, five if you can. Resist the urge to correct between shots. A single hole tells you almost nothing; a group tells you where your rifle is truly hitting and reveals any flyer for the outlier it is. Once the group is complete, measure how far its center sits from the bullseye. On a grid target you just count the squares; with an MOA or MRAD reticle, hold the crosshair on the bullseye and read the offset directly off the reticle.

6. Adjust Elevation, Then Windage

Correct one axis at a time — it keeps things simple and helps you spot any turret that isn’t tracking correctly.

Elevation moves your impact up or down; windage moves it left or right. Turrets are marked with arrows and letters (U for up, R for right), and you turn the dial in the direction you want your point of impact to move. If your group landed low, dial toward “UP”; if it landed left, dial toward “R.”

Now convert your measured offset into clicks. Say you’re shooting a 1/4 MOA scope at 100 yards and your group is 2 inches low and 1 inch right. Two inches is about 2 MOA, or 8 clicks up; one inch is about 1 MOA, or 4 clicks left. Fire another group and confirm the correction moved you where you expected.

One important note if you did your first group at 25 yards: the clicks work differently up close. At 25 yards, a 1/4 MOA click only moves impact about 1/16th of an inch, so you’ll need roughly four times as many clicks to move the same distance on paper as you would at 100 yards.

7. Confirm Your Zero at 100 Yards

If you started at 25 or 50 yards to get on paper, move your target out to your true zero distance now and repeat the fire-and-adjust process. Your zero isn’t finished until you’ve confirmed it at the distance you actually chose. Fire a fresh group, make any small final corrections, and then shoot one more group to verify it holds. This whole process usually runs about 20 rounds start to finish.

8. Reset Your Turrets and Document the Zero

Once you’re satisfied, don’t leave your turrets sitting on some random number. Most scopes let you loosen the turret caps and rotate them so your new zero reads “0” — that gives you a clean baseline to return to any time you dial for distance. If your scope has a zero stop, set it now so you always have a physical floor to spin back down to. Finally, write it all down: rifle, scope, the exact ammunition, and the conditions. That record is your reference point every time you head back to the range.

Common Sighting-In Mistakes to Avoid

• Chasing the bullet: Adjusting off a single shot and then constantly following your impacts around the target. Always adjust off the center of a group, never one round.
• Zeroing with mixed ammo: Switching bullet weights mid-session throws your zero off. Because trajectory changes with the load, it’s worth understanding how cartridges differ — our breakdowns of 5.56 vs .308 and what “grain” means in ammo explain why a heavier round drops faster and why you can’t assume one load’s zero carries to another.
• An unstable rest: Bench wobble shows up as a scattered group you’ll mistake for a bad zero.
• Blaming the rifle too soon: A quality zero comes after you can produce a consistent group. If your fundamentals aren’t there yet, no amount of turret twisting will fix it.

Put Your Zero to the Test at Strip Gun Club

Understanding how to sight in a scope is one thing — feeling a precise rifle reach out and connect with a distant target is another entirely. At Strip Gun Club, the only luxury shooting range on the Las Vegas Strip, our Sniper Package lets you do exactly that. You’ll run precision-scoped rifles like the Barrett .50 BMG, the FN SPR in .308, and a 5.56mm DMR, with dedicated round counts, high-visibility targets, and one-on-one coaching from experienced range officers who’ll walk you through your aim and stance on every platform.

No 45-minute drive into the desert, no summer heat — just focused, professionally supervised precision shooting right on the Strip, with complimentary hotel transportation included.

Frequently Asked Questions

What distance should you sight in a scope?

For most rifles, 100 yards is the go-to zero — it’s the standard reference for ballistic data and works well for target shooting, hunting, and general range use. If your range only allows shorter distances, a 25- or 50-yard sight-in gets you on paper, and you can confirm at 100 later. Long-range shooters typically zero at 100 and then dial or hold for everything beyond.

Do you chase the bullet when sighting in a scope?

No. “Chasing the bullet” means adjusting your scope after every single shot and following your impacts around the target — a fast way to waste ammo and never settle on a true zero. Instead, fire a full group of three to five rounds, find its center, and make one adjustment off that center. Then confirm with another group.

Which way do you turn the scope to sight in?

Turn the turret in the direction you want your point of impact to move. Elevation dials are marked “UP” (turn that way to raise your impact), and windage dials are marked “R” for right (turn that way to move impact right). Each click represents a set amount — usually 1/4 MOA or 0.1 MRAD — so count your clicks based on how far off you are and how far the target is.

How does sighting in a scope work?

Your bullet travels in a curved arc while your line of sight through the scope is straight. Sighting in adjusts the reticle so the bullet’s arc crosses your line of sight at a chosen distance, making your point of aim and point of impact the same there. You do it by firing a group, measuring how far off it lands, and clicking the windage and elevation turrets to bring the reticle in line with where the rounds actually hit.

How do you easily sight in a scope?

Start with a rock-solid rest, bore sight to get on paper fast, and use a grid target so you can count squares instead of doing mental math. Begin at 25 yards to rule out wild misses, adjust elevation and windage separately, then confirm at 100. A laser bore sighter and a purpose-built zeroing target are the two tools that speed things up the most.

Is sighting in at 25 yards the same as 100 yards? Not exactly. A 25-yard sight-in gets your rounds on paper and puts you in the ballpark, and for some cartridges a near-zero at close range roughly corresponds to a usable 100-yard zero. But because of height over bore and the bullet’s trajectory, the two are not identical — your impact at 25 yards will typically sit low relative to your true 100-yard zero. Always confirm at your actual intended distance before you call it done.