Last Updated on March 11, 2021
Sighting in a rifle is pretty easy, and you shouldn’t be intimidated by needing to sight it in after you mount it up. In this guide, we’ll walk you through the process of sighting in (also called zeroing in) your scope no matter what kind of scope you have.
Regardless of what scope or optic you bought, it should have at least two adjustment turrets somewhere on it. One of these is for windage, and one is for elevation. The windage turret will adjust the reticle left and right, and the elevation turret will adjust the reticle up and down. You will use these turrets during the process of zeroing in your scope.
With firearms, the term “scope” is often used to describe any optic, even if it doesn’t have any magnification. With that said, the technically accurate term for an optic with no magnification is a “sight”. Scopes and sights all need to be zeroed in to be accurate at a certain distance.
The purpose of a scope is to show you exactly where your bullets are going to hit. When a scope is first mounted, it can be as much as several inches above where the projectile exits the barrel, and it won’t be perfectly aligned to your specific rifle yet.
The projectile also drops as it flies through the air, so even if you’re hitting right where you’re aiming at 100 yards, you’ll hit a bit low at 200 yards, and lower at 300 yards, etc.
Yes, red dot sights need to be zeroed in after they have been mounted because the zeroing process has nothing to do with magnification; it is simply the process of making the center of your reticle accurately predict where your bullets will land. The process is essentially the same for scopes with high magnification and red dots with no magnification.
For the purposes of this article, we’re going to assume that your scope was properly installed and is reasonably level and straight with the rifle barrel. Once that is done, the process for sighting in the scope is actually pretty straightforward.
You’ll want to go out to a range and set up your target 100 yards away for a scope with magnification, and 25-50 yards for a red dot.
You want to set up your target 100 yards out unless you have a red dot or other specific reason not to. 100 yards is considered the standard zeroing distance unless you do not intend to ever shoot beyond 50 yards or will most often be shooting at longer distances. For your first time, it’s recommended to zero at 100 yards and then you can always zero again for a different range if it would work better for you.
Aim the reticle at the exact center of the target, and do not compensate to hit the middle of the paper after your first shot. Shoot at least 3 rounds, and more if you need to in order to get a consistent grouping. If you’re not an experienced shooter, you may need more than 5 rounds to get a clear sense of how off the scope is.
Go to your target and measure how far to either side the grouping is from the center of the target. Record the distance in inches (this will be important later). Then measure how far above or below the grouping is from the center of the target and record it in inches as well.
Go back to your rifle and scope and use the adjustment turrets to shift the reticle to where it needs to go to reflect where the bullets are hitting.
Your adjustment turrets will move the reticle a set amount, which is measured in MOA (minutes of angle). 1 MOA is 1 inch at 100 yards, so if your turrets are .25 MOA, you will need four clicks of the turret to move the reticle the equivalent of 1 inch at 100 yards. If they are .5 MOA, you will need only two clicks
Don’t worry too much about MOA right now, just learn how large the adjustment clicks on your scope are and adjust them as much as needed to line up the sight.
Put another set of rounds through the rifle with your reticle aimed at the center of the target and see where your grouping ends up. Hopefully, the grouping is centered around the middle, but if not, you’ll just repeat the measuring and adjusting until it is.
If your scope has enough magnification for you to clearly see where your groupings are without needing to walk out to the target, you can try adjusting it while looking through your scope, but that requires a bit more practice and expertise.
Not all scopes have resettable turrets, but if yours does, it can be nice to reset the turrets back to zero without moving the reticle. This maximizes the amount you can compensate for windage and elevation on the fly for specific shots. You do not have to do this step; your scope is properly zeroed and ready for action as-is, but it’s a good way to prep the scope for whatever you need it for.
Depending on the quality of the scope you bought and how well it was mounted, the scope might lose zero after you’ve been firing it for a while. If this happens, you can just sight it in again, but you should also check the mounting job (especially if you did it yourself), make sure everything is tight and snug, and look online to see if others are reporting the scope losing zero.
Scopes should not lose zero after they’ve been sighted in, so if a scope does it usually means something is wrong. If the scope is on a rifle with more recoil than it was designed for, that can cause it to lose zero, as can defects in manufacturing. It’s good to check to see why the scope lost zero before sighting it again.
Getting your scope sighted in isn’t difficult, and can be a great excuse to get to the range.
Featured image credit: tobbo, Pixabay
Robert’s obsession with all things optical started early in life, when his optician father would bring home prototypes for Robert to play with. Nowadays, Robert is dedicated to helping others find the right optics for their needs. His hobbies include astronomy, astrophysics, and model building. Originally from Newark, NJ, he resides in Santa Fe, New Mexico, where the nighttime skies are filled with glittering stars.
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