Zeroing
How to Zero a Rifle Scope
Quick answer
Zero a rifle scope by firing a group of three to five shots from a stable rest, measuring from the aiming point to the group center, converting that distance to clicks with a tool like the scope click adjustment calculator, and dialing the turret in the direction it marks for point of impact.
Zeroing is not one shot and a correction. It is a group, a measurement, a calculated correction, and a confirming group, repeated until the average center of impact sits where you want it. Correcting off a single shot means correcting for wherever that one shot happened to land within your rifle's inherent group size, which is not the same thing as correcting the scope.
One rule decides whether a correction is trustworthy: if the group is bigger than the correction you are about to make, do not make it. A half inch correction based on a two inch group is noise, not signal, and dialing it in adds error rather than removing it.
How to zero a rifle scope
- Clear the rifle and set up on a safe, legal backstop. Open the action and confirm the chamber is empty before doing anything else at the bench. Set up only where you have a safe, legal backstop and you know what lies beyond the target. Zero on a supervised range whenever one is available.
- Build a stable position. Support the rifle front and rear with bags or a rest, such as a Caldwell DeadShot Filled Front and Rear Shooting Rest Bags at $37.99, so the rifle's own accuracy is what you are measuring rather than your ability to hold it steady.
- Confirm the rifle is on paper before firing a group for record. If the scope was just mounted, bore sight it first so the first shots land on the paper rather than off it entirely. A bore sighter gets you close; it is not the zero.
- Fire a group, not a single shot. Fire three to five rounds at a single, consistent aiming point on a gridded target such as the Champion Redfield Style Precision Sight-In Targets, 10 Pack at $8.01. A single shot cannot be distinguished from an outlier; a group can.
- Measure from the aiming point to the group center. Find the middle of the group, not the single closest or furthest shot, and measure the distance and direction from your aiming point to that center. This is the actual correction the scope needs.
- Check the group size against the correction before dialing anything. If the group itself is wider than the correction you are about to make, stop and shoot another group instead of adjusting. Dialing a correction smaller than your own group size is adjusting to noise.
- Convert the measured distance to clicks. Use your turret's click value at the distance you are shooting to convert inches of correction into a specific number of clicks. Turrets marked in different increments need different math, so confirm the click value rather than assuming it.
- Dial in the direction the turret marks for point of impact. Scope turrets are marked with the direction the point of impact moves, for example an arrow labeled "up" moves the impact up. Confirm the direction on your specific turret before dialing, since the convention is consistent but the labeling detail is worth a second glance the first time.
- Fire a confirming group at the same aiming point. Shoot another group of three to five rounds at the same point of aim. The new group center should sit at or very near your intended zero. If not, repeat the measurement and correction.
- Record the zero. Note the distance, the load used, and the date. A zero is specific to the load; a different bullet weight or velocity at the same distance will not necessarily land in the same place.
How many inches is one click, at your zeroing distance?
Click value is exact arithmetic once you know the increment and the distance, and it is the number that turns a measured miss into a specific number of turret clicks.
A quarter MOA click moves impact about a quarter inch at 100 yards, while a 0.1 mil click moves impact about 0.36 inch at the same distance, and neither value is interchangeable with the other.
Sourced figure
| Turret increment | Inches at 100 yards | Inches at 300 yards |
|---|---|---|
| 1/4 MOA | 0.26 in | 0.79 in |
| 1/2 MOA | 0.52 in | 1.57 in |
| 1 MOA | 1.05 in | 3.14 in |
| 0.1 mil | 0.36 in | 1.08 in |
| 1 mil | 3.60 in | 10.80 in |
MOA and mil are not the same unit and a turret is only one or the other. Confirm which your scope uses before doing any correction math.
Why a stable rest changes what a group actually tells you
Every group fired includes two sources of spread mixed together: what the rifle and ammunition are capable of, and whatever your own position adds on top of that. A rifle rested loosely on a rolled jacket might genuinely group into an inch on its own, but the same rifle in the same hands might print three inches because the position itself is inconsistent shot to shot.
A front and rear bag combination, or a front rest with a rear bag, removes almost all of that human variable by giving the rifle a stable, repeatable platform. This matters directly to zeroing because the whole method depends on trusting the group center as a real measurement. A group inflated by an unstable position produces a center that is partly noise, and correcting off it can chase that noise around the target across several range sessions instead of converging on a real zero.
Sources
- Exact trigonometric conversion of MOA and mil to inches at distance
- Owner-review consensus on group-based zeroing method
Frequently asked questions
How many shots do I need to zero a scope?
Fire groups of three to five shots rather than single shots, since a single shot cannot be told apart from a normal outlier. Measure from your aiming point to the center of the group, not to the single closest or furthest hole, then confirm with another group of the same size after making a correction.
Should I aim for the group center or the closest shot when correcting?
Always the group center. The closest shot to your aim point might simply be the one that happened to land there within your rifle's normal spread. The center of several shots is a far more reliable estimate of where the rifle is actually shooting, and it is the number the correction math should use.
How do I know which direction to turn the turret?
Scope turrets are marked with the direction the point of impact moves, commonly an arrow or a word like "up" or "right." Confirm this on your specific scope before dialing, since the labeling can sit in slightly different places across brands even though the underlying convention, moving the impact in the marked direction, is consistent.
What if my group is bigger than the correction I need to make?
Do not make the correction yet. If the group is wider than the distance you are about to dial, the measurement is not reliable enough to act on. Shoot another group first, and only dial once the correction you need is clearly larger than the spread of your shots.
Does my zero change with a different type of ammunition?
Often yes, sometimes significantly. A zero is specific to the load it was set with, including bullet weight and the velocity it produces from your barrel. Switching to a different weight or a different manufacturer's load can shift point of impact enough to matter, so reconfirm zero any time the ammunition changes.
What is the difference between MOA and mil clicks?
They are two different, non-interchangeable measurement systems. A quarter MOA click moves impact about a quarter inch at 100 yards, while a 0.1 mil click moves impact about 0.36 inch at the same distance. Confirm which system your specific turret uses before doing any correction math, since mixing them produces a wrong answer that looks reasonable.
Researched, not professional advice. This page is compiled from published manufacturer specifications, published optical and ballistic formulas, and owner-review consensus, not hands-on testing. Figures described as a rule of thumb are shooter convention rather than sourced numbers, and they are labelled that way wherever they appear. Ballistic figures come from a point mass model using the ballistic coefficient the maker publishes, so treat them as a starting point and confirm them on paper at a measured distance. Confirm your firearm is unloaded with the action open before you mount, level, torque or bore sight anything. Verify a zero only on a supervised range or a safe, legal backstop, know what lies beyond your target, and follow the law where you hunt and shoot, including rules on land access and permitted cartridges.