← zeroconsiderations.com

How to Sight In a Rifle Before Opening Day

Most of the ammunition wasted at a bench in October goes to doing this in the wrong order: shoot one, turn the turret, shoot another, turn again, until the box is light. The version that works: bore-sight it, shoot one careful group, measure how far the group's center sits from your aim point, turn that offset into clicks and dial once, then shoot a second group to prove it. One range trip, and a rifle you trust on opening morning.

When to sight in: three weeks out, not the Thursday before

Three weeks before you need it. Ranges get crowded before the season, and a busy line with short cease-fires is a poor place for careful work. Sighting in is also the trip where you find out something is wrong: a ring screw never torqued, a scope that will not hold a setting, a load the rifle does not like. Each needs a second trip, and that takes room. Reading this the week of the opener? Go anyway, go early, and keep the confirmation step.

What you need

• The rifle, scope mounted and every screw torqued. A loose ring is the most common reason a sight-in will not settle.
• One box of the ammunition you will actually hunt with. A different load prints a different point of impact, sometimes by inches at 100 yards.
• A steady rest: front and rear bags, or a bipod and a rear bag.
• A target with a square grid, so you can read the offset off the paper. Our free printable sight-in targets include a one-inch grid in Letter and A4.
• Eye and ear protection, something to write with, and the tools for the mount.

Step 1: Get on paper without burning ammunition

A freshly mounted scope can miss the whole sheet at 100 yards. Two ways to avoid hunting for a miss:

• Bore-sight it. On a bolt gun, pull the bolt, rest the rifle so it stays put, and center the bull in the bore. Without moving the rifle, turn the turrets until the crosshair sits on the same spot. For anything you cannot look through, a laser bore-sighter does the same job.
• Start close. Shoot one or two rounds at 25 yards; one inch off there is about four inches off at 100. Correct roughly, then move back. See the 25-yard sight-in targets and guide, and if 25 is as far as your range goes, a 50-yard zero from the 25-yard line.

On paper is the whole goal here. Do not chase precision yet.

Step 2: Shoot one careful group, not one shot

This is the step that saves the ammunition, and the one most people skip.

No rifle puts every bullet through the same hole. Rifle, load and shooter together print a cone, and a single shot lands somewhere inside it at random. If the rifle shoots 1.5 inches at 100 yards, a perfectly sighted-in rifle can still put one shot three-quarters of an inch from the crosshair. Turn the turret off that shot and you have corrected for randomness; the next shot lands somewhere else in the cone, and you spend the afternoon walking circles.

The center of a group averages that randomness out. Three shots tell you where the rifle is hitting; one shot tells you where one bullet went. So: same aim point for every shot, the best rest you have, the hunting load, and all three rounds downrange before you touch a turret. Give a thin barrel a minute between shots, and if you know you pulled one, shoot a fourth. Five is better if the rifle is new to you.

Step 3: Measure how far the group sits off your aim point

Walk down once, or pull the target on the cease-fire. You need two numbers: how far the center of the group sits from your aim point up or down, and how far left or right. Never the diagonal; it mixes both corrections into one number you cannot dial.

With a ruler

For three shots the center is the middle of the triangle; to be exact, average each hole's height and side distance from the aim point. Measure to hole centers, not edges. On a one-inch grid this is counting squares.

With a photograph

With Zero Considerations this step is a picture. Photograph the target after you shoot; the app finds the target face and the bullet holes, measures the group's offset from your aim point in real inches, then shows you what it found so you can add or move a ring. Scale comes from the coded corner markers on our printed targets, from a cartridge laid in the frame on any other target, or you type the size in by hand.

Step 4: Turn the offset into clicks and dial once

Scope clicks are angles, not inches, so what one click moves depends on the distance. Most hunting scopes adjust in quarter-MOA clicks; many newer scopes use tenth-MIL clicks. The turret cap or the manual says which.

One MOA is 1.047 inches at 100 yards, not a clean inch, so a quarter-MOA click moves the impact about 0.26 inches there.

Worked example: the group center is 2 inches low and 1.5 inches right at 100 yards with quarter-MOA clicks. Up: 2 ÷ 0.26 ≈ 8 clicks. Left: 1.5 ÷ 0.26 ≈ 6 clicks. Round to the nearest click, dial both, leave the turrets alone.

Turret arrows show which way the impact moves, so a low group means dialing UP and a right group means dialing LEFT; and an offset measured at 50 yards needs the 50-yard column. At the bench, the free scope click calculator hands back the dial, and the app does the whole chain from the photograph, in your scope's own click value.

Step 5: Confirm. One correction is a hypothesis, not a sight-in.

Shoot two or three more rounds at the same aim point. If the new group centers within about a click of where you were aiming, you are sighted in; write down the load, the distance and what you dialed. If it is still off, dial the small remainder and shoot again. A first correction can land a little off for boring reasons: turrets that do not move exactly their marked value, or rings still settling. That is why no careful shooter, and no honest app, calls a rifle sighted in off a single correction.

Which distance to sight in at

Sight in at the distance that fits the shots you will take, not the distance the range happens to offer:

The method does not change with distance; only the inches per click do. For the ammunition-efficiency version, with the arithmetic laid out shot by shot, read the five-shot method, in detail.

Frequently asked questions

How many rounds does it take to sight in a rifle?

Five or six if you bore-sight first: a three-shot group, one correction, a two- or three-shot confirmation. Budget ten for a freshly mounted scope. Past twenty, the problem is usually the method or the mount, not the rifle.

Do I have to re-sight if I change ammunition?

Yes, or at least check. A different bullet weight, a different velocity, even a different lot of the same load can move the point of impact, sometimes by an inch or more at 100 yards. Switch loads, shoot a three-shot group with the new one.

Can I sight in at 25 yards for a 100-yard zero?

You can get close. The bullet starts below the scope and climbs to meet the line of sight, so a rifle dead-on at 25 usually prints high at 100, by an amount that depends on the load and the scope height. Use 25 to get on paper, then confirm at 100. The 25 versus 100 guide works through what dead-on at 25 really means; the app can predict the 100-yard result from a 25-yard group, and labels it a prediction.

Does a red dot sight in the same way?

Same method, different numbers. Many red dots adjust in half-MOA or one-MOA clicks, and the usual distances are shorter: 50 yards for a carbine, closer for a pistol. For a handgun, the pistol red dot zero distance guide covers where to set it and why.

What if my scope runs out of adjustment?

Stop dialing and look at the mount. A scope that hits the end of its travel at 100 yards is almost always on a base or rings that are not true to the bore. Set both turrets to the middle of their travel, check that bases and rings are seated and torqued, and start again from bore-sighting. Do not hunt with a turret pinned against its stop.

Sight in from a photograph, then keep the numbers

Disclosure first: I wrote this page, and I make the app it describes.

Zero Considerations does this page's work in one flow: photograph the target, get the measured group in real inches and in MOA and the clicks in your scope's own click value, and a results screen that tells you to confirm with live fire. It keeps the zero, the load and the conditions for next season. The clicks come from the optic you picked: 1,043 optic entries · 852 firearms · 512 loads · 301 reticles drawn from the manufacturers' published subtension sheets.

It will not bluff you. When it is not certain it has your target, it shows you the photo with the box it found and asks "Is this your target?" before it measures anything. Where it will not stand behind your zero, it says so plainly. Every result is a starting point you confirm with live fire.

Counted rather than rounded: 301 reticle patterns from 82 manufacturers, and 965 of the 1,043 optic entries in the app resolve to one of them. We chose sourcing over volume: every pattern is drawn from a manufacturer's published subtension figures.

Everything that measures and calculates runs on your phone. Your firearms, loads, photos and results never leave your device. The one time the app touches the internet is the optional weather lookup you tap yourself, which sends an approximate location to a weather service and stores nothing. $9.99 once. No subscription, no account.