Knowing how to zero a rifle scope at 100 yards is an essential first step towards improving your accuracy and precision in long-range shooting.
Other than that, you should also know where to aim when learning to master shooting at different distances.
Aiming at close range can be difficult enough for beginners, let alone zeroing at greater distances, such as 100 yards.
Before doing so, you should first understand how to work a rifle scope and zero a gun at shorter distances.
What Does Zeroing a Scope Mean?
Zeroing a scope means setting the riflescope at a good alignment with your rifle.
Basically, doing this will help you aim accurately and analyze where the bullets should hit every time you shoot.
Having a scope zeroed with a rifle means its crosshair reticle is centered on the point where all the bullets hit.
The importance of zeroing a scope stems from the fact that bullets do not travel in a straight line.
Instead, they are projectiles. Gravity starts pulling them down as soon as they leave a gun’s barrel.
To make up for the bullet drop, you have to zero your scope to show where the bullet should go and not where the barrel should be pointing.
Why Should You Zero in at 100 Yards?
The distance of 100 yards is just a generalization, and no set rules are saying you should zero at 100 yards.
You can zero your scopes at a distance of 25 or 50 yards, and it could be easier or harder depending on some conditions.
Still, the factory-set specifications of most riflescopes are typically measured at the 100-yard range.
This means that zeroing at this distance should be very easy for most shooters, even for total beginners.
Scope manufacturers typically set the parallax adjustment at 100 yards, so this the best distance to zero your gun for the first time.
Additionally, it is a good distance to hunt, as it is not too far to make aiming difficult and not too close to spook any targets.
If you want to hunt from farther distances, say 200 or 250 yards, you should also zero your rifle at this distance.
A scope zeroed at 100 yards will not have the accuracy of shooting at 250 yards.
Having it zeroed in at your preferred hunting distance compensates for the larger bullet drop it would take if you leave it zeroed at only 100 yards.
Understanding Your Scope
If you do not know how to zero your riflescope, you probably just bought your very first scope.
Before everything else, you must first understand the inner workings of the particular scope you have on hand.
Your time at the range can be much more enjoyable if you are familiar with your riflescope.
1. Reticle Type
Riflescopes come in varying specifications, and one of the essential features is its reticle.
Do you have a fixed crosshair reticle etched onto the viewing lens?
If so, you will only have to understand the adjustments for windage and elevation.
Otherwise, you might also want to understand milliradian (Mil) or minute of angle (MOA) reticle measurements as soon as you group your shots perfectly.
Determine which of the knobs and turrets on your scope are for adjusting windage, elevation, and parallax.
The windage turret will let you align your sights left or right to compensate for wind resistance.
Similarly, the elevation turret enables you to adjust your aim up and down to counter bullet drop.
Find out in what increments your scope makes adjustments for each click of a turret.
Some scopes will have parallax adjusters for maintaining the target location even when viewed from changing positions.
3. Magnification Power
Additional knobs will let you turn on illumination and alter magnification settings in other high-powered scopes.
While built-in illumination improves visual acuity, higher magnification power will enable you to see if your crosshair aligns with the target.
Fixed magnification riflescopes will not have the variable objective sizing.
In comparison, variable magnification scopes typically come at a higher price.
How to Zero a Rifle Scope at 100 Yards
You can proceed with zeroing your rifle as long as you completely understand what your scope can do.
The following procedure outlines a surefire method of making your gun accurate at the 100-yard range.
Step 1: Set up Your Target at 100 Yards
Since we are trying to zero your rifle at 100 yards, your target should sit at a stable position in that distance.
Choose a target that can easily show you where your bullets hit.
For zeroing purposes, the best target option is a piece of target cardboard or sheet with a bullseye and ring calibrations.
The calibrations will help you adjust your sights as soon as you have good grouping.
Step 2: Set Your Rifle in a Stable Position
The best way to zero your scope and rifle is to make adjustments while shooting from a very stable position.
If you have a rifle rest, use it.
Keeping your rifle in a stable position eliminates inaccuracies caused by breathing and slight movements while shooting.
The more stable your hardware is, the easier you can finish zeroing your rifle.
Step 3: Look Through the Scope and Set up the Shot
You will know that your gun is in an excellent position if you look through the scope and its crosshairs align with the target.
Reposition your rifle until you see the target in your sights, but remember to put it in a stable position.
You may have to repeat this step several times after you make your adjustments for windage and elevation.
Step 4: Adjust for Magnification, Windage, And Elevation
The goal is to obtain a clear image of the target through the scope.
If the target is not clear, you will want to try setting your scope’s magnification to the correct range.
At the same time, turn the windage and elevation turrets to the appropriate direction to compensate for air resistance and bullet drop.
Step 5: Level Your Crosshair with the Bullseye
Your reticle should point to the target’s center so that your scope points to where you want your bullet to go.
At this stage, the direction of your barrel should already account for projectile movement.
Step 6: Fire Three Rounds
Once your reticle is pointing at the center of the bullseye, fire a single shot and check if it hits the target.
The point of impact is your reference position for making the adjustments to your scope.
If you want to assess for movement changes after each shot, let go of two more rounds.
Step 7: Assess the Shots
If none of your shots hit anywhere within the target sheet, it could mean that you did not set up your scope the way you should have.
Otherwise, successful hits within a distance of 10 inches from the target may only require scope adjustments.
Step 8: Decide Whether to Make Major or Minor Adjustments
Refit your scope if you did not land any shots within the entirety of the target sheets.
Be sure that the mounts are secure and that the scope is at the recommended eye relief distance from the cheekpiece of your buttstock.
If your rounds landed within the target sheet with a good grouping, you could make adjustments to the scope.
Step 9: Calculate, Adjust, And Shoot Again
Suppose your scope makes adjustments in half-inch increments per click, and your shots landed four inches above the target and two inches to the right.
This means you will have to adjust your scope by eight clicks going down and four clicks to the left.
Fire a single shot and examine where it lands on the target.
Step 10: Make Finer Adjustments to the Scope
Confirm the previous shot with a second or third round, and decide whether you still need to make finer adjustments.
If all three shots hit the bullseye, then you can proceed with checking by repositioning your rifle.
Otherwise, if the hit marks have a fine grouping but are vertically and horizontally off by a few inches from the bull, make finer adjustments.
The rifle’s accuracy should have improved by now, and you should be closer to hitting the target.
Step 11: Reposition Your Rifle
Relocate your rifle at a different stable position.
Choose a distance between 90 and 110 yards to check how much different your shots will be after firing a few more rounds.
As long as the grouping is good, you will only need to make fine adjustments as you change positions.
Newbie or not, zeroing a rifle does not have to be challenging or intimidating.
Once you get the hang of it, it can be really straightforward and enjoyable.
Learning how to zero a rifle scope at 100 yards is the same as zeroing at shorter or longer distances.
However, it is much easier to zero a gun at close range than over long distances.
You have to keep in mind that a rifle’s accuracy diminishes if you zeroed it at a much shorter distance and your target goes farther.
If you plan to shoot over 100 yards, you’ll have to zero your rifle at a range much closer to your target distance.