“By failing to prepare, you are preparing to fail.” – Ben Franklin
There are plenty of places to learn how to sight in a scope on the internet. Really, there is no shortage of information there.
That being said, a lot of them are written in what looks like 8 point font, were filmed in the late 1980’s, or simply do not go into enough detail on the whole “what you need to do when zeroing a scope” bit.
I don’t like that. I like detail when it come to things I’m trying to accomplish.
And when you learn how to zero a rifle scope, you really want to make sure you get things right!
Why? Because little mistakes now can cost you big time down the road. And I don’t say that trivially.
For instance, let’s look at a reticle cant:
The image to the right is an example of one. A cant is when your reticle does not line up directly up or down, so when you adjust the scope it adjusts at an angle.
This image was taken from riflescopelevel.com.
At that same link they talk about how a 5 degree cant creates a horizontal bullet displacement of 4.2 inches! That’s nothing to sneeze at.
Zeroing A Scope For Beginners
Now, odds are that when you’re starting out, you will make plenty of mistakes. And that’s okay, trust me I did. And still am for that matter.
The important thing is to learn from those mistakes. Or better yet, to learn from other people who have made mistakes and get to your goal quicker.
This article is designed to teach you how to sight in a scope in less than 5 total shots. Really, it could be done in 3, but as we’re going to learn, it’s better to shoot groups that way you have a consistent amount of data to go off of.
Note – when we say “zero” we mean that we are adjusting the scope so that when you aim at a point, that is exactly where the bullet is going to go.
Bullets travel in an arc, they don’t fly in a straight line. So the point you aim at, isn’t where it’s going to hit, unless you zero it at a distance.
Scopes are “zeroed” at certain distances, usually 100 yards. So when we say a scope is “zeroed at 100 yards” we mean that when you aim at a certain point at 100 yards, that’s the point the bullet will hit.
One caveat here – it is highly unlikely that as a complete beginner, it will only take you 5 shots. You probably don’t have the muscle memory to shoot the kind of tight groups you need to really know where your bullet is landing.
Fun fact – first time I zeroed a scope I used about 20 rounds of ammo. It was painful, but I learned a lot.
This article isn’t for just your first time zeroing a scope. It’s for you to use time and again as you get better and better.
Enough talking, let’s get started. Follow along with the video as well if you’d like
It has never failed to surprise me the difference in preparedness makes when I am trying to achieve something. It’s like the difference between being able to predict your outcome and not.
The first part of the process to sighting in a scope is making sure your setup is running correctly.
Remember that example from above? Yeah, we don’t want you to have a cant when shooting. That leads to big problems, and it’s often difficult to know what’s wrong.
Step 1: Mount the scope
Preparation starts with mounting the scope. Now, you’ll want to follow the very detailed tutorial we’ve put together at this link here. But I’ll give you a brief overview.
What you’ll need: high quality rings (like Seekins), a mount, a level (kind of like this level, it is more effective if you have one mounted on the gun and on the scope), your gun (duh) and the hex wrench of the size you need for your rings.
The absolute most important thing when mounting the scope is to make sure that the scope is level relative to the gun, and that the gun is level relative to the ground.
Which is why it’s important to have a level for both the rail of the gun and the scope. The gun level will center the scope, and the scope level will level the scope relative to the ground.
Start by aligning the rifle to the ground so that the bubble level says it is perfectly level, or as close to perfectly level as you can get.
If you are using a gun vice, this is where you tighten the gun into place. If you are using a bipod (like me), then once it is level make sure the bipod is tight once you have it level.
Now it’s time for the scope. Attach the scope level to the scope.
Then Attach the bottom of the rings to the base or the mount. Place the scope in the rings, then place the top of the rings on top of the scope.
Tighten them to the point where they are holding the scope, but that you can still move it. Note: it is not important for you to have the scope level at this point.
Now we are going to adjust for eye relief. Place your head behind the scope in the way you will when you are shooting the gun, make sure you are comfortable and not straining your neck.
Move the scope forward and back until the picture takes up the whole of the glass and there is no black ring around the edges. Good.
Step 2: Bore Sighting
Boresighting is simply a way for you to make sure that your scope is pointed where your barrel is pointed. This is important to make sure you don’t burn a bunch of ammo guessing where your scope is pointed at 100 yards.
If, for some reason, your scope is dialed up too much and you take it to 100 yards to shoot your group, you will miss the target completely. When you miss the target, you have no idea by how much, and will simply have to guess your adjustment until you land on paper.
That is a huge waste of ammo. Boresighting saves you this, and thus saves you money.
There are two main ways to boresight, depending on how you want to do it:
- Using a Boresighter
- Getting on paper at 25 yards
I usually use option 2, but we’ll go through both.
Option 1 – Using A Boresighter
A boresighter is simply a cartridge-looking object that fits in your gun barrel. You use it to shine a laser dot on the wall and to adjust your scope to meet the dot.
Simply place your boresighter inside the barrel, turn it on, then adjust your scope turrets (see how to adjust a rifle scope) to make the center of the reticle line up directly with the dot.
Option 2 – Getting On Paper At 25 Yards
I usually use this method. The boresight is effective, but the boresighter is just one more thing to keep track of and I’m not interested in getting the scope to line up perfectly with the little red dot anyways.
What we do in option 2 is to set a target anywhere between 10-25 yards (preferably 25) and we shoot. Typically since it’s so close, it’s going to land on the target, unless you are at the upper ends of the spectrum in turret adjustments.
Once you’re on paper at a low distance like this, make an adjustment to get you close to your “zero” or where the center of the crosshair was aiming. Don’t worry about shooting a group, it’s not needed to be perfect at this stage.
Your scope will most likely not be lined up exactly with where the barrel points, but it will be close enough to make sure your group will be on paper at 100 yards, or whatever the distance is you are going to zero at.
Step 3: Aim & Check your level
Before you shoot your group, make sure your levels are showing that your rifle is level to the ground. Since we mounted the scope relative to the rifle, just making sure one is level will be fine and you don’t need both levels on the rifle anymore.
Making sure your gun is level is absolutely critical. If it is not level, it will develop a cant.
A cant occurs when your reticle is not matched perpendicular to the ground, i.e. the scope/rifle isn’t level. This means that when you make turret adjustments, you will not be adjusting directly up or down or left or right, your adjustment will have an angle to it.
So although you think you adjusted to zero, you actually adjusted up 1 MOA and left 2 MOA, you didn’t.
Basically you’ll be missing the center, and you won’t know why. This burns ammo and depletes your self esteem. Do yourself a favor and make sure the rifle is level.
Step 4: Shoot your group
Now we move the target to whatever distance you want it zeroed at. I usually do 100 yards, and that tends to be pretty standard for long shots. But some hunters do it at 50.
Neither is better than the other, it’s entirely your preference and relative to your situation.
Now what we mean by a “group” is that we shoot anywhere between 3-5 shots. 3 shots should be sufficient, but sometimes people go more.
We do this because we want to actually see where your bullet is landing. One shot is an accident, two shots are a coincidence, three shots on the same spot is a pattern and it’s far more likely that that is actually where the bullet is landing independent of human error.
When you shoot your group, you will be aiming (most likely) at the center of the target or a target. Your shots are most likely not going to land in the center, but will land somewhere of the target.
Shoot three shots pointing at the exact same place on the target each time. If your shots are within 1 MOA of each other (at 100 yards that ~1 inch), you can be reasonably assured that that is where your scope is currently tracking.
Note: this is where the promise of the blog post, “How to sight in a scope in under 5 shots” may not deliver on it’s promise. If you are shooting bad groups and you can’t easily tell where the shots are landing, you will go over those 5 shots.
Step 5: Make your adjustment, shoot your zero
Now we measure how far off that group is from where you were intending. You can use your reticle (if it has the subtensions to allow it) or use the target itself.
Some people take a tape measure and measure the distance. If you do that, use a tool like our MOA and Mil calculator to convert that distance to MOA or Mils.
Note: use the unit of measurement that your scope subtensions are in and that your turret adjustments are in. It just makes it easier on you.
If you have a reticle that has these measurements on it already, that’s great! Just use that instead. Either way, figure out how far vertically and horizontally you need to adjust your turrets to make your shot go to zero.
Another note – please see the walkthrough on how to adjust a rifle scope because it will come in handy here.
Bingo, you’re ready for the final step!
Step 6: Evaluate, adjust as necessary
And there you go! You have a sighted in rifle scope.
Every time you go to shoot, you will want to confirm this zero. Rings are not always as dependable as manufacturers would have us believe, and when moving a rifle the scope can get bumped around a bit.
It’s also common for a scope to lose it’s zero. There could be about a million different reasons as to why this happens – something happened with the gun, the erector tube broke, the mount came loose, you name it.
What you need to do here is accurately diagnose the problem. Sometimes it just happens and it’s a freak thing, other times it might be a mechanical malfunction.
Just make sure you confirm your zero everytime you go out to shoot. If it lost it’s zero, go back through the steps above. Simple as that.
Drop your comments below – what new techniques did you learn? How are you going to adjust the way you adjust your scope next time?
Also, if you’re in the market for an optic, we do 12% off for all first time customer. Head to the shop if that’s you!