How to Zero a Scope

Sighting in a new optic can be a frustrating experience for those used to iron sights, and even experienced shooters can run into some issues while trying to get a scope perfectly zeroed. Thankfully, there are a few foolproof ways to streamline and simplify the process, ensuring that even someone who has never zeroed a scope before will have no problem placing shots dead center on the target after their next trip to the range.

Read on for our in-depth look at how to sight in your rifle scope, adjust for distance and wind, and confirm those adjustments.

Why It's Important

For shooters who are only interested in plinking or who rarely fire at targets beyond 50 yards, being an inch or two off target may not matter. But for those who are longer distance shooting or who want to ensure a clean kill while hunting, getting a proper scope zero is critical.

At extreme distances, an improper zero can even be a safety hazard - missing by a few inches at 50 yards translates into missing by several feet when you're pushing 750 yards.

In other words, making sure your bullets are landing exactly where you intend them to is safer, more humane, and less frustrating for the shooter, which is more than enough reason to put the effort into learning how to zero your rifle scope. 

Pre-Zeroing Things to Do

Before we get started, let's look at what you'll need. Obviously you can't sight in a scope without a rifle, a scope, and a quality scope mount or rings. You also need some targets - high-visibility are recommended - and ideally a spotting scope if you want to avoid making that long walk out to the target in between every set of shots.

You'll also need ammunition, which should all be of the same make, since mixing grains and loads can result in dramatically different ballistics. It's a good idea to use the same kind of ammo that you plan to shoot with most often, so avoid the temptation to break out the high-end match-grade ammunition unless you are preparing for a competition.

Finally, you are going to want something to stabilize your rifle as much as possible - a bench rest, vice, or even a set of sandbags will all make your life much easier when trying to adjust your zero with accuracy. My personal favorite setup is a few sandbags under the forend of the rifle and another under the butt of the stock, but don't be afraid to experiment with your setup until you find something comfortable. Now that everything is in position, we can take a look at the next step.

Bore Sighting

Bore sighting is an optional step, but one that I highly recommend if you want to save time and money during the zeroing process. To bore sight a rifle simply means to be able to center the target's bullseye by looking down the barrel from the back of the receiver. Begin by ensuring that the rifle's muzzle is pointed at the target and that the rifle is unloaded.

For a bolt-action rifle, accessing the bore is as easy as removing the bolt. For AR-style rifles, you'll need to remove the charging handle and bolt and then re-attach the upper first in order to see down the rifle's barrel. While looking down the barrel, position the rifle until it as close to the center of the bullseye as you can get. Then, while keeping the rifle in the same position and as still as possible (this is where a vice is very handy), look through the optic and make turret adjustments until the crosshairs are also centered over the bulls eye.

While this won't get you a perfect zero, this method gives you a great starting point to make more accurate adjustments, and guarantees that you'll at least be getting shots on paper in roughly the vicinity of the target's center when you take your first test shots through the scope.

If you want to buy a bore sight for your rifle then checkout our guide on best bore sight!

Initial Shots

Now that you've bore sighted your rifle and got a rough zero, it's time to take the first shot through your scope and see what kind of adjustments need to be made. Generally speaking, most rifles can be zeroed in at 100 yards, which will allow you to take accurate shots from 50-200 yards without needing to worry about re-zeroing the scope or trying to estimate holds, and outside of the plains states, the vast majority of hunting takes place within those ranges as well.

Aim for the center of the target and fire at least three rounds. Shooting multiple rounds serves a few different purposes - having a full shot grouping lets you know that your point of impact is consistently accurate and that you aren't dealing with a loose or faulty scope, and it also lets you ignore any fliers and otherwise eliminate user error. A single bullet hole just doesn't give you enough information to accurately adjust your scope.

Making Adjustments

Once you know where your rounds are landing, we can move on to the next step of the zeroing process, which involves matching up your point of aim with your point of impact. First and foremost, keep in mind what your scope's click values are. 

Usually these are printed somewhere on the turrets, but 1/4th MOA (minute of angle) and 1/2 MOA are the values you are likely to run into on most scopes. If the click value is 1/4th MOA, that means each click you hear when making turret adjustments will shift the impact point by 1/4th of an inch at 100 yards. For example, if your bullet hole hit 1 inch low, you will need to adjust the elevation turret by 4 clicks in order to get it on target.

While it's much less common, some scopes also measure their click value in mils, or milliradians, instead, with one mil being the equivalent of 10 centimeters at 100 yards.

A common reticle feature on modern scopes is a set of hashmarks or dots that allow the shooter to correct for quick windage and elevation adjustments on the fly. This is known as a holdover reticle, and they can be a convenient tool that eliminates guesswork at long range.

There is also something called a BDC reticle, or bullet drop compensator reticle, which performs the same basic function of giving you quick references based on range without having to tinker with the scope or the gun itself, but they are typically designed for the ballistic profile of a specific cartridge and sometimes even a specific load.

If you are using a scope with one of these reticles, be sure to read the manual for further instructions, and keep in mind that some scopes use MOA click values but mil holdover markings. Not everyone is a fan of using this type of reticle, and they are arguably best suited to bench rest shooting, but many hunters also love not having to make adjustments or estimate holds when a buck surprises them at a range they weren't expecting to shoot at.

Confirming Your Zero

Once you have made your elevation and windage adjustments are able to consistently put shot groupings on the bullseye at 100 yards, the last step is to confirm your zero with a simple box test. To carry this out, begin by placing one shot dead center.

For your next shot, make a vertical adjustment on the elevation turret up 6 MOA (24 clicks) and fire again while still aiming at the bullseye. Make a windage adjustment of 12 MOA to the right and fire again. Then adjust elevation down 6 MOA and take another shot.

Finally, adjust 6 MOA to the left and fire one last round. If you've zeroed your scope properly, this should result in a nice, clean square pattern on your target, which lets you know that the scope is in the correct position, that its tracking is functioning properly, and that the adjustment values are accurate.

And that's all there is to it! If you've followed this guide so far, you should have a properly zeroed gun and all the tools you need to zero your scope in the future.

If you want to buy a bore sight for your rifle then checkout our guide on best bore sight!

A Few Things to Keep in Mind

While 100 yards is the most popular zero range for a rifle, it's certainly not the only correct option. Your chosen distance should be based on the type of gun you are shooting, the distances you are most likely to shoot at, and what kind of ammo you are using.

A high velocity round fired through a rifle with an enormous variable-zoom scope can safely have its sights set at 200 or even 300 yards, especially if you are, for instance, planning on hunting antelope on a wide-open plain. Likewise, a rimfire rifle scope or air rifle scope probably shouldn't have its zero dialed in at 100 yards.

Still, it's worth noting that with advances in holdover reticle design and easy access to a digital drop chart, a scope sighted in at 100 yards is still incredibly versatile and more than capable of making an accurate shot at longer distances, especially if your rifle is firing bullets with flatter trajectories and a higher velocity.

Likewise, many modern scopes now come with zero stop turrets, which allow you to set the turrets back to zero and then make adjustments for elevation and windage at longer distances, then dial the turrets back to zero afterward and be back to a perfect 100 yard zero.

While it's often overlooked, I also can't emphasize enough how important a high-quality mount or set of scope rings are for ensuring a stable, reliable platform to shoot from. After investing in your rifle's scope, not to mention the rifle itself, a cheap pair of pot metal rings with poor tolerances is going to do nothing but prolong your time at the range trying to get rounds on target. Save yourself the frustration and the extra trips to the range and buy a good set from the get-go.

Parting Shots

We hope this guide has been a helpful resource when it comes to learning how to zero your scope. Whether you're shooting at paper targets, ringing steel at 1000 yards from a rifle rest, or hunting wild game, properly zeroed rifle scopes are crucial for keeping rounds on target and making sure each hit is true.

If this guide helped you zero a scope or even simply learn a bit more about the process, sound off in the comments and let us know! Our goal is to provide quality, in-depth content on a wide variety of hunting and shooting-related topics, and your feedback helps us decide what to cover next.

If you're a more visual learner, Vortex Optics (one of my favorite scope manufacturers) has made this handy video that breaks down scope zeroing. And if this article has inspired you to pick up a new scope for your rifle, check out our recent guide on the best scope options under $1000!