How to Zero a Rifle Scope: Step-by-Step Guide (2026)

A rifle scope is only as good as its zero. You can buy the best glass on the market, mount it on a tack-driving bolt gun, and load match-grade ammunition — but if the scope isn't zeroed properly, none of it matters. Your point of aim (POA) won't match your point of impact (POI), and every shot will miss by an unpredictable amount. Zeroing is the process of aligning your reticle with your barrel so the bullet hits exactly where the crosshairs sit at a specific distance. This guide walks you through it from start to finish, covers the most common zeroing distances, and explains how to troubleshoot when things go wrong.

Why Zeroing Matters

Your barrel and scope sit on two parallel but offset planes. The scope is typically 1.5–2 inches above the bore centerline. Because the bullet travels in a parabolic arc (it rises, then falls), and the scope looks in a straight line, the two paths only intersect at specific distances. When you "zero" at 100 yards, you're telling the scope: "adjust so the bullet's arc crosses my line of sight at exactly 100 yards."

Without a proper zero, you're guessing. A scope that's 2 MOA off at 100 yards puts your bullet 2 inches from where you aimed. At 300 yards, that error compounds — now you're 6+ inches off, which is the difference between a clean harvest and a wounded animal. For precision shooters, an imperfect zero negates everything else you've done right.

Equipment You'll Need

• Bore sighter (laser or optical) — Saves ammo by getting you on paper before your first shot. A 0 laser bore sighter pays for itself in one range session.
• Stable shooting rest or lead sled — You're zeroing the rifle, not testing your marksmanship. Remove as much human error as possible. A front rest with a rear bag is minimum; a lead sled is ideal.
• Consistent ammunition — Use the exact load you plan to shoot in the field. Different bullet weights and velocities shift POI significantly. Don't zero with cheap FMJ and then hunt with premium soft points.
• Torque wrench — Verify your scope mount and ring screws are torqued to spec (usually 15–25 in-lbs for ring screws, 30–65 in-lbs for base screws depending on manufacturer). Loose mounts are the #1 cause of zero loss.
• Targets with grid lines — Shoot-N-C or similar targets with 1-inch grid squares make measuring adjustments simple. Don't use blank paper — you need reference points.
• Pen and notepad — Track your shot groups and adjustments. It's easy to lose track of how many clicks you've dialed.
• 20+ rounds of ammo — A bore-sighted rifle usually gets zeroed in 9–15 rounds. Bring extra for confirmation groups.

Step 1: Bore Sight First (Save Ammo and Frustration)

Bore sighting gets your scope close enough that your first shots land on paper. Without it, you might waste an entire box of ammo chasing impacts that are 2 feet off target at 100 yards.

Laser Bore Sighter Method

Insert the laser bore sighter into the muzzle or chamber (depending on type). Point the rifle at a target 25 yards away. The laser dot shows where the bore is pointing. Now adjust your scope turrets until the crosshairs sit on the laser dot. You're done — the scope and bore are roughly aligned.

Optical Bore Sighting (No Tools Required)

Remove the bolt from your bolt-action rifle. Look through the bore from the breech end and center a target at 25–50 yards in the bore. Without moving the rifle, look through the scope and note where the crosshairs sit relative to the target. Adjust turrets until the crosshairs point at the same spot the bore sees. This method is free and surprisingly effective, but only works with bolt-action rifles where you can look straight through the bore.

Step 2: Set Up at 25 Yards

Don't start at 100 yards. If your bore sight is even slightly off, you could miss the entire target backer at 100 yards and have no idea which direction to adjust. Start at 25 yards where misses are small and corrections are easy to see.

Set your rifle in the rest, ensure the rifle is stable and not canted, and place your target at exactly 25 yards. A 25-yard zero gets you on paper; you'll fine-tune at distance afterward.

Step 3: Fire a 3-Shot Group

Fire three shots at the center of the target, taking your time between shots. Let the barrel cool if needed — heat causes POI to shift on thin barrels. You're not shooting for group size here; you're shooting to find where the rifle is currently hitting relative to your aim point.

After three shots, walk down and inspect the target. Identify the center of your 3-shot group. Measure how far the group center is from the bullseye — both horizontally and vertically. Write it down: for example, "2 inches high, 1.5 inches right."

Step 4: Adjust the Turrets (MOA vs MIL)

Every scope has two turrets: one on top (elevation, moves POI up/down) and one on the right side (windage, moves POI left/right). Each click of the turret moves the point of impact a fixed amount. The two systems are:

MOA (Minute of Angle)

One MOA equals approximately 1.047 inches at 100 yards (most shooters round to 1 inch). Most hunting scopes use 1/4 MOA clicks — each click moves POI by 0.25 inches at 100 yards, or roughly 0.0625 inches at 25 yards. If your group is 1 inch right at 25 yards, that's about 4 MOA — so you need 16 clicks left on the windage turret.

MIL (Milliradian)

One MIL equals 3.6 inches at 100 yards (or 0.9 inches at 25 yards). Most MIL scopes use 0.1 MIL clicks — each click moves POI by 0.36 inches at 100 yards. MIL is more common on tactical and precision scopes. The math works the same way; the units are just different.

Which Direction to Turn

The turrets are labeled with arrows or the words "UP" and "R" (right). Move the turret in the direction you want the POI to move. If you're hitting low-left, dial UP and RIGHT. This is the most common point of confusion for new shooters — you're moving where the bullet hits, not where the crosshairs point.

Calculating Clicks at 25 Yards

At 25 yards, each 1/4 MOA click moves POI about 1/16 inch (0.065"). To make things simpler, many shooters use this shortcut: multiply the correction you'd make at 100 yards by 4. If you're 1 inch off at 25 yards, that would be 4 inches off at 100 yards — so dial 16 clicks (at 1/4 MOA per click). Fire another 3-shot group and confirm.

Step 5: Move to 100 Yards and Confirm

Once your 25-yard group is centered on the bullseye (or at your desired offset — see zeroing distances below), move to 100 yards. Fire a fresh 3-shot group. Chances are you'll be close but may need 2–4 clicks of fine adjustment. Make the correction, fire another 3-shot group to confirm, and you're zeroed.

Always confirm with a final 3-shot group after your last adjustment. If you adjust and walk away, you don't actually know if the zero is correct. The confirmation group is the proof.

Common Zeroing Distances and Why They Matter

Choosing a zero distance depends on your cartridge, your typical shooting distances, and whether you use holdovers or dial turrets. Here are the most common options:

25-Yard Zero

Primarily used as a starting point for AR-15s. A 25-yard zero with 5.56 NATO roughly corresponds to a ~300-yard zero because the bullet's arc crosses the line of sight twice. The US military uses a 25m/300m zero for the M4. It's effective for combat-oriented shooting but puts the bullet about 2.5 inches high at 100–200 yards.

36-Yard Zero

Popularized for AR-15 carbines. A 36-yard zero with 55gr .223 gives you a trajectory that stays within ±2 inches from the muzzle to about 250 yards. It's a "set and forget" zero for defensive carbines where you don't want to think about holdovers inside 250 yards.

50-Yard Zero

Common for .22 LR, pistol-caliber carbines, and some rimfire or short-range applications. Also used by some hunters who do most shooting inside 150 yards in thick cover.

100-Yard Zero

The standard for most bolt-action hunting rifles and precision rifles. It's the most intuitive — 1 MOA = 1 inch at your zero distance. Turret adjustments are dead simple: 1 click = 1/4 inch (for 1/4 MOA scopes). Most ballistic data and drop charts reference a 100-yard zero. If you only shoot one cartridge and want to keep things simple, zero at 100.

200-Yard Zero

Popular with western hunters and long-range shooters using flat-shooting cartridges like 6.5 Creedmoor, .300 Win Mag, or .28 Nosler. A 200-yard zero with a fast cartridge keeps you within a few inches of POA out to 250+ yards. The downside: your bullet hits ~1.5–2 inches high at 100 yards, and turret math requires you to remember your offset at shorter distances.

BDC Reticle Zeroing Considerations

If your scope has a BDC (Bullet Drop Compensator) reticle — like the Vortex Dead-Hold BDC, Nikon BDC, or Primary Arms ACSS — the hash marks or circles below center are calibrated for a specific cartridge, bullet weight, and velocity at a specific zero distance. Read your scope's manual to find out which zero distance and load the BDC is designed for.

Most BDC reticles are calibrated for a 100-yard zero with a common load (e.g., 55gr .223 at 3,200 fps or 168gr .308 at 2,680 fps). If you zero at a different distance or use a different load, the BDC marks won't correspond to the ranges printed in the manual. You can still use them — but you'll need to verify each mark at the range or use a ballistic calculator to determine what distance each mark actually represents with your specific load.

For maximum accuracy with a BDC, zero at the distance the manufacturer specifies and use ammo as close to their reference load as possible. Then verify each hash mark at actual distance rather than blindly trusting the printed values.

Zero Distance vs. Bullet Drop: Common Calibers

The table below shows approximate bullet drop (in inches) at various ranges for three popular rifle calibers, all zeroed at 100 yards. Negative values mean the bullet hits below POA; positive means above.

Notice how 6.5 Creedmoor drops significantly less than .308 at distance — this is the high-BC advantage. The .223 is flat-shooting but runs out of energy quickly. The .308 drops the most but carries more energy downrange than .223. Use a ballistic calculator like Applied Ballistics or Hornady 4DOF for exact numbers with your specific load.

Troubleshooting: When Zero Won't Hold

You've zeroed the scope, confirmed it with a group, and the next range trip the POI is different. Here are the most common causes:

Loose Scope Mounts

This is the #1 culprit. Recoil loosens ring and base screws over time, especially on magnum rifles. Check all screws with a torque wrench every 200–300 rounds. Use blue Loctite (removable) on all scope mount screws. Never use red Loctite — you'll destroy the threads trying to remove them later.

Inconsistent Ammo

Switching between brands, bullet weights, or even lot numbers can shift POI by 1–3 inches at 100 yards. Always re-confirm zero when switching ammo. If you hunt with a specific load, zero with that load.

Barrel Heat

Thin sporter barrels shift POI as they heat up. Your first two cold-bore shots might land dead center, then shots 5–10 walk upward as the barrel heats and expands. For hunting rifles, zero with a cold bore — fire one shot, wait 3–5 minutes, fire another. Your cold-bore POI is what matters in the field.

Stock Contact / Pressure Points

If the barrel touches the stock (not free-floated), changes in humidity, temperature, or how you rest the forend can change the barrel's vibration pattern and shift POI. Solution: free-float the barrel or ensure consistent forend pressure. Most modern rifles ship free-floated, but budget hunting rifles and older models often don't.

Scope Tracking Issues

Cheap scopes sometimes don't track consistently — you dial 10 clicks up, but the POI only moves 8 clicks' worth. Or the return to zero isn't repeatable. This is an internal mechanical problem with the erector tube. The fix: buy a better scope. A "box test" or "tall target test" diagnoses tracking problems. If your scope can't pass a box test, replace it — no amount of adjustment will give you a reliable zero.

Parallax Error

If your scope has an adjustable parallax (AO) or side-focus knob, parallax must be set correctly for your shooting distance. Incorrect parallax means your POI shifts depending on your eye position behind the scope. Set parallax so the reticle doesn't appear to move against the target when you shift your head slightly. Most hunting scopes are factory-set for parallax-free at 100–150 yards.

Pro Tips for a Better Zero

1. Clean the bore before zeroing. A fouled bore and a clean bore can shoot to different POI. Clean it, fire 3–5 fouling shots, then zero.
2. Shoot from a solid rest, not a bipod on concrete. Bipods on hard surfaces bounce during recoil and open groups. Use a bag or padded surface under the bipod feet.
3. Don't chase single shots. Always adjust based on 3-shot group centers, never individual impacts. One flyer doesn't mean your zero is off — your trigger pull might have been.
4. Record your turret settings. Once zeroed, note the turret position numbers or count clicks from the mechanical stop. If the turrets get bumped, you can return to your verified zero.
5. Re-zero after any scope removal. Even return-to-zero mounts aren't perfect. If you pull the scope for any reason, verify zero before hunting.
6. Consider altitude and temperature. Ammunition performs differently at 90°F vs 20°F — powder burns at different rates. If you zero in summer and hunt in winter, verify zero in conditions similar to your hunt.

Final Thoughts

Zeroing a rifle scope is one of the most fundamental shooting skills. It takes 20 minutes and 15 rounds of ammo. Don't skip it, don't rush it, and don't assume the scope is "close enough." Close enough is a miss on an animal or a lost match stage. Take the time to do it right, confirm with a final group, and re-verify before every season or competition.

Need a scope that actually tracks? Browse our rifle scope deals from brands like Vortex, Leupold, and Primary Arms. If you're running a red dot on a carbine, check our red dot sight deals. And make sure you're zeroing with the ammo you plan to use — compare prices on .223, .308, and 6.5 Creedmoor rifle ammo across every retailer we track.