If you’re anything like me then you’ve had some difficulty figuring out how to adjust a rifle scope. It’s a more complicated topic than it sounds, and every optic has nuances that can make it difficult to figure out. This article is going to clearly cover how to sight in the most common types of rifle optics, both magnified, and red dot optics. By the end of this article, you’ll understand which zero to choose for your rifle, and how to adjust a rifle scope in 5 easy steps. Keep reading for more.
The first thing you should do, before you even buy a new rifle, or a new scope, is decide what the purpose of the firearm is. This sounds obvious, but I can’t tell you how many rifles I’ve seen that are set up completely inappropriately for its intended purpose. I’m talking short range applications with 25x magnification scopes here!
Most rifles with magnified optics will be used between 50 and 200 yards. If you live out in open country, this might increase to 400 yards or more. Unless you’re a competitive long range shooter, you probably aren’t shooting at this distance with any regularity. This means that you’re probably shooting a mid range magnification optic, through one of a couple standard calibers. This makes adjusting a rifle scope, or zeroing the rifle, fairly straightforward. Here’s a quick overview on how to adjust a rifle scope in 5 easy steps.
How to Adjust a Rifle Scope in 5 Easy Steps
- Choose your rifle and optic based on its intended use
- Mount the optic in the correct location for eye relief and parallax
- Choose the zero with the most intuitive holds for your application
- Shoot on an inch grided target, starting close and moving to zero distance
- Shoot 4-5 shot groups and make bold scope adjustments
There are certainly more details that go into each step which we’ll cover below. I will also recommend some decent optics and mounts that can be used for a variety of applications. First, we’re going to cover mounting and adjusting a standard rifle optic.
Choose Your Rifle and Optic
This is our first step. We need to figure out what optic we’re going to use. For most use cases a variable power optic from 1-10x magnification will suffice. If you’ve never looked through a very high power optic, you’ll find that you start to see a lot of wobble, and even your heartbeat in the reticle as you get close to that 15-20 power mark. Here are a few recommendations for quality optics, that won’t break the bank.
Rifle Scope Recommendations
All these optics manufacturers have solid recommendations, and I’ve personally used a Vortex Viper on one of my AR15s for nearly 10 years, with no issues what so ever. These optics are biased towards the AR15 platform, but they can be used on nearly any rifle you choose.
If you’d like to see the Tier Three Tactical approved gear list then check it out here. We’ve linked to tons of items we’ve used, and approve of. It’s always growing, so don’t forget to check back from time to time.
Parts of a Magnified Rifle Scope
There are a few commonalities among all types of rifle scopes. There are two lenses we need to know about. The lens closer to the target is called the objective lens. The lens closest to your eye is the ocular lens. You make adjustments with knobs mounted to the scope body, called turrets. Generally the knob on top of the scope is the elevation turret. This adjusts the impact of the bullet up and down vertically.
The knob on the side of the scope is the windage turret. As you might imagine, this adjusts the impact of the bullet laterally, left and right. You’ll also find a ring, close to the ocular lens, that allows you to adjust the magnification of the scope. You adjust the magnification by twisting the ring. Some scopes will also feature an eye piece that can help you adjust the reticle for your specific eyesight, or glasses prescription.
Important Rifle Scope Features
If you read my article about picking the best hunting binoculars, you’ll understand the importance of choosing a larger objective lens. This will aid your scope in gathering more light, and transmiting a clearer image to your eye. You’ll also find that rifle scopes feature different levels of eye relief. This is the distance from the scope that your eye should be able to see the full view, without scope shadow.
Cheaper optics will often have a very limited eye relief, and if you move your eye too close, or too far away then you’ll see the black ring of scope shadow. This really limits your field of view. It makes finding your target that much harder because you feel like you’re looking through a straw.
The next most important feature is the type of reticle. Many scopes will feature a bullet drop compensating reticle (BDC). This is a reticle that is matched to the ballistic performance of certain rounds. It allows you to simply aim with a different part of the reticle to adjust for wind or longer ranges. Otherwise you need to make adjustments with the turrets.
All scopes have reticles that are either first focal plane, or second focal plane. First focal plane scopes have reticles that enlarge as you crank up the magnification. Second focal plane scopes have reticles that remain the same when magnification is increased.
Adjusting Turrets
The turrets will move the zero of your reticle based on distance and atmospheric conditions. If you find yourself shooting at much longer ranges you can dial in elevation, and then you can still aim with the center of your reticle. This keeps you from using Kentucky windage, otherwise known as aiming off target, hoping that you picked the right hold.
For our purposes we will be using the turrets to adjust the bullet strike to our desired zero. Once that is done, we will lock them back down. Contrary to what you see on TV, you probably won’t spend much time moving turrets around.
Most shooters don’t ever touch their turrets once their rifle is zeroed. Many decent quality rifle scopes have zero stops that allow you to spin the turrets back to their location, without losing your zero, but this is by far the least used feature of magnified rifle optics. If you pick a good reticle pattern you really don’t need to bother with spinning turrets.
No that we know the basic features of rifle scopes, and we have some idea what each part of the scope does, we can move on to step two, mounting the optic.
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Mount the Optic in the Correct Location
This might seem simple to most people, but you need to make sure you’re mounting the optic in the correct location for the type of rifle you have. There are two key considerations for mounting your scope. You need to place the optic mount in the right location, and you need to mount the optic so you don’t have scope shadow when you look through the sight, while holding the gun.
Some long guns have a continuous, or monolithic upper, with one solid piece of picatinny rail. This means that you can place your scope mount in any location on the rail and it’ll be fine. Other hunting style rifles have specific locations to mount scope rings. Neither is better than the other. Here are photos of both options.
When purchasing scope rings, or a scope mount, you should buy something that’s made by a quality manufacturer. You don’t have to buy the most expensive rings you can, but if you bought them from Wish.com, they aren’t very good.
It’s critically important that you pick rings that have the same diameter as the scope you’re mounting. Often times you’ll see 30-34mm mounts mounting systems. You should follow the scope ring instructions and mount the rings closer towards the butt stock of the weapon.
If you picked the right location, the optic can be centered in the rings/mount when it’s in the correct position. The best way to figure out if your optic is mounted correctly is to partially tighten the mount so the scope doesn’t slide, and then shoulder the gun. If you see scope shadow, move the optic further or closer towards your eye until you see the full field of view.
You may have to move your rings a little bit so the bell of the scope doesn’t stop the movement. Play around with the location until you have a full clear picture, and the mount is equidistant on the scope. You can see in the picture below that turrets are equidistant from the scope mounts. This is what you want to achieve.
Once this is done, I recommend putting a dab of blue Loctite on any screws you use to mount the optic. This will keep them from backing out. Obviously, you should follow the instructions for your gear. Some optics, and mounts shouldn’t have any Loctite used. Now we’ve mounted the optic, let’s pick our zero.
Choosing Your Zero
Picking your zero range really blows people’s minds up. The video below will explain this so you have an understanding of what happens to a bullets trajectory, and how that affects your zero distance. The best way to remember this is that you need to pick a zero distance that allows you to make the fewest, or most intuitive adjustments for the targets you’re shooting at.
In the video you can see that there are two key lines. One is the eye target line (or point of aim), which passes through your scope and continues to whatever target you’re looking at. The next is the ballistic arc or trajectory of the bullet. Because your optic has a mechanical offset above the chamber of the rifle, then your barrel has a slight upward angle. This is why the bullet travels in an arc. See the chart below.
Your zero is anywhere on that chart that you choose to line up your eye target line with the arc of the bullet. For AR15 style rifles, that are generally shot at 200 yards and in, the 50 yard zero makes a lot of sense. This means that if you put the center of the reticle on your target, you’ll only ever have 2-4 inch or deviation within 200 yards. This is easy to remember, and practically requires no adjustment. This zero makes sense for that application.
You can see in the chart above that as the bullet leaves the rifle it is below the eye target line, because of the optics mechanical offset. Once it reaches 50 yards there is no offset because we’ve mechanically moved the reticle to the arc of the bullet. After 50 yards the bullet continues to travel upwards, achieving max height and 100 yards, where it falls from there. We can also see that at about 140 yards the bullet is back in line with the eye target line, or the second zero point.
If you are a long range shooter, then perhaps a 100 yard zero would make sense. This means that you only ever have to remember bullet drops at those distances or beyond. If you have a bullet drop compensating reticle then you literally just line the right part of the reticle up, for the different distances, and squeeze the trigger.
Either way, there are many other articles that you can Google regarding the best zero distance for your bullet, caliber, and your target distance. For the rest of this article we’ll cover how to zero an AR15 rifle, using a magnified optic, with a 50 yard zero. Now let’s talk about how to adjust a rifle scope at the range.
Getting On Target at the Range
I can’t tell you how often I’ve seen some wacky stuff while people try to zero at the range. I do recommend using a range with known distances, otherwise your accuracy might suffer. If you thought you were zeroing at 100 yards, but you really zeroed at 70 yards, then your calculations will be a few inches to a few feet off.
I highly recommend using something like these gridded targets. They are one inch grids that allow you to quickly understand how far you need to move the impact point of your rounds. You don’t have to use them, but they can be easier, as many scopes are measured in MOA, or minute of angle. Here’s a quick video explaining that concept.
The first thing you need to do once you’re ready to shoot your first group is make sure you’re using a good shooting position. I highly recommend shooting from a bench, or prone with a good shooting rest or bipod to stabilize the gun. You need to shoot as accurately as possible by eliminating as much human error as you can. After all, you’ll be using the impact of each bullet hole to determine how to adjust your rifle scope.
Shooting Groups and How to Make Adjustments to Your Rifle Scope
For a 50 yard zero, I would shoot my first group at 25 yards. This ensures that I will at least hit the paper and allow me to make adjustments. Most people shoot three-shot groups, but this isn’t a good idea. If you wing your first shot, then you can’t really tell where the center of your group is, and consequently where to move it. Instead, shoot 4-5 shot groups. Here’s an example first group on target.
You can see that we are low and left. We need to move the point of impact up and right. Remove your turret caps, and you’ll notice that there are mostly likely arrows on them that point right or left. Don’t over think this. If we want the bullet to go right, then turn the knobs in the right direction, following the arrow. Do the same thing for up, since we are low. You can use a screw driver, or even a piece of spent brass to make adjustments.
If you’re a nerd like me, you can figure the number of clicks equal to one MOA ,and then you can figure out how many clicks you need to move it exactly. This really doesn’t save you much time. I recommend making bold adjustments, if you’re more than 6 inches off target at 25 yards. Try 10 clicks up and about the same amount to the right. It doesn’t matter if that was too much, you can always reverse it a few clicks if you over corrected. Next you can shoot your next group of 4-5 rounds.
Based on these corrections, we are still a little low and left. I would try another 8 clicks up and 8 clicks right, and then I would move my target to my desired zero distance. Shoot your next 4-5 shot group and see how far off you are. Be mindful that as the target moves further away each click moves the bullet impacts further. Be a little less bold.
You will repeat this refinement process, at your zero distance, until you achieve a solid group in the center of your target. Remember, if you over correct then you can simple dial the clicks the other way. Once you’ve achieved your zero, put your caps back on and lock the turrets if your scope allows you to do that. You’ve have a zeroed rifle!
How to Zero a Red Dot
You can use the exact same process to adjust a red dot scope. However, there are a few tricks that I recommend, to make it a bit easier. First, turn the red dot optic down as dim as you can, and still see a defined circle. If you have the reticle at max brightness then you can’t see the center clearly.
Next, you will mount the optic relatively close to your eye, generally over the center of the receiver. The mounting location matters less because red dots don’t have parallax. Parallax is simply when objects look like they’re in different locations when viewed through different angles of a scope. Magnified optics can have parallax issues, and some have parallax adjustment on them. This is beyond the scope of the article, just make sure you’re looking through a magnified optic the exact same every time.
Once your dot is mounted, you will repeat the same 4-5 shot group process, starting with a close target, to get on paper. You’ll then move to your actual zero distance, to fine tune your zero. If you’re using a flip over magnifier with a red dot, I normally choose to zero with the magnification, and I accept that the zero without it might be an inch or so off.
You need accuracy at distance, which means you’re shooting through the magnifier. When you’re close, and unmagnified, that discrepancy doesn’t matter. No one ever missed by 1/32d of an inch at 7 yards. If you have, then you need more practice!
Final Thoughts
Long range rifle shooting, and adjusting your rifle scope can be a very complicated topic, especially if you chase details that don’t matter. Remember that all we’re doing is moving the reticle to line up with the arc of the bullet. Everything else is just noise.
A proficient rifle shooter will understand exactly where they need to aim to achieve hits at any distance. Similarly, they also understand how to dial adjustments on their scope if they need to. These are all laudable goals to shoot for, but first you need to start with an accurate zero.
If you have any questions or comments, then put them in the comments section below, and I’ll get you an answer. Now get out there and get training!
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