How to Sight In a Scope

Whether you’re a hunter or sport shooter, your rifle is useless if you can’t hit your target.  If you’re using aftermarket rifle optics, they will have to be zeroed in to be accurate.  In this post, we’ll go over every step needed to achieve accuracy with your weapon optics.

Hits on Paper

Whether you’re using a red dot scope or an enhanced zoom rifle scope, you’ll need a reference or starting point to begin making adjustments.  This is because you need to know where your bullets will land in relation to what you see through the sight.  Paper targets with the standard .5 inch grid pattern on the background are preferred for this process.

You need to determine the appropriate distance at which to zero your optics.  This should be a distance that you anticipate or plan to shoot from most often.  A minimum of 25 yards is recommended for optics with no zoom function, but 50 is better.  Whether you zero at 25, 50, 100, or more yards is less important than zeroing at a distance you’re comfortable at and most likely to shoot from.

Make sure your optics are securely fastened to your firearm.  Otherwise recoil can move the position of the optic and crosshairs slightly.  Keep in mind that the slightest change in crosshair position will have a huge effect on accuracy which is amplified at increasing distances.

Now let’s start shooting.  Keep in mind that we shoot in groups to account for shooter:  if you shoot three shots - all aiming at the same area of the paper - and they land relatively close together, then we’re good to move on with our zeroing.  It doesn’t matter if the shots land exactly where intended so long as they are hitting the same area of the target consistently.

If you didn’t, then let’s back up and get you on the paper using something like a boresighter.  If you’re on the paper, move on to the next step.  A boresighter gives you a reference point to hone your crosshairs onto, closing the distance between the spot the sights are zeroed to and the spot the shots will land at.

Fine Tuning to Zero

Now it’s time to start making your adjustments.  All optics have elevation and a windage adjustments, allowing control of your reticule’s x and y axis.  Vertical movement of the reticule adjusts for elevation, horizontal for windage.

Most adjustment wheels are stepped so they turn in slight increments with the sound and the feel of a click. Thus your adjustments can be measured and held to a predictable and controlled standard.  Combined with using the .5 inch grid paper we mentioned earlier, this will help you easily adjust for wind and elevation on the fly.  Depending on your particular optic, “one click” may move the bullet a half inch at 50 yards and a full inch at 100 yards, or .25 inches at 50 and .5 inches at 100 yards.

The specs defining how far a click moves the bullet at a given yardage will be found in your particular optic’s user manual.  Bear in mind that caliber, bullet weight, and other factors will affect results, so use the same ammo you plan to use later when zeroing in.  Once this information is determined, you can then measure how many clicks it will take to move your bullet two inches down and five inches to the left, for instance.

If I am using an optic where one click equals a half inch at 50 yards, then I know that to move my bullet 4 inches in a single direction at 50 yards will take 8 clicks.  Because the lines on the grid are spaced .5 inches apart, you have a quick and easy way to determine how many inches you need to move the bullet, thus supplying you the information needed to determine the number of clicks required to achieve the desired result.

Keep in mind that the three shot rule applies throughout this entire process to ensure consistency.

At What Point Am I Considered “On Target”?

This depends on what rifle you’re using, the shooting distance, and what cartridges you’re using.  For example, an M4 rifle is not designed to be used like a long-barrel, .308 bolt-action rifle.  The M4 is a battle rifle, designed to be used in short to medium range situations, where the .308 bolt action is designed for long-range precision.

So, being able to consistently hit in groupings at short to medium distances with the M4 is considered “on target”.  Likewise, shot groupings from a long range precision platform should be much closer together at shorter distances, yet still close enough to be considered “groups” at longer distances.  These concepts validate the reasons for differences between a sniper and a rifleman, as well as the differences in the weapons that they use.