How to Sight in a Scope

Sighting in a Rifle Scope

Sighting in a Best AR 15 Scope is not a big deal if you pay attention to a couple of things.

rifle scope basics

Zeroing a scope

This is most feared by the novice shooter because it looks and sounds complicated. Well, it is neither. Select a large sheet of paper and mount it at 25 yards. Assuming that your scope has been bore sighted to some degree, aim for the center of the paper. Use a small black dot for an aiming point. Old school teaching says: aim small shoot small.

zeroing a rifle scope

Fire a single round and see where the bullet impacts the target area. If you can’t hit the target at 25 yards, move closer until you get a bullet on target. Now, noting that information, take off any turret caps and turn to the desired direction so as to change the bullet's impact. We call these “clicks”, because of the sound they make as you turn to each marking on the turret.

The turret ring is marked for right or left and up or down adjustment. If the bullet doesn't change its impact point, tap the scope turret lightly, for example with a knife handle or any other hard, heavy tool. But don’t overdo it. Sometimes the springs in the turret don’t want to respond

sighting in a rifle

As the impact point moves, keep it towards the target center, first adjusting elevation and then the diameter.

When you hit the black dot, shoot three rounds for group effect. If the bullets are all in the same area, move the target to the 100-yard mark. Bullets will hit high in most cases. With a shot on the paper at the longer-range limit, adjust to again hit the target center at that range. Now you are zeroed correctly.

Using a rifle rest

rifle scope adjustment direction

Use a sandbag or a solid rest. I run 30-pound bags for dead-on rest requirements, and an 8-pound bag for portable work. Bags are not expensive and fit well on a permanent bench or a mobile system in the field.

When shooting ultra long-range, 1 mile or more, I almost always use the heavy bag system. Bi-pods are OK, but I don’t like to shoot prone (laying down) in heavy rattlesnake country. That's always a good way to get bitten.

Some of the new tripod standing mount systems are workable, but in my opinion they turn a shooting act into a purely mechanical one. Just like when a guy learned to shoot buffalo a long time ago with 45-70 open ladder sights and a pair of crossed sticks from the sitting position. However, it did put meat on the table with consistency.

When zeroing, don’t shoot off-hand, meaning with no solid rifle rest. Get on a bench, table, or platform of some type, and use a good chair as well if shooting from a table/bench rest. When you have adjusted for the shot, send it and watch the results. I am not saying don’t shoot off-hand ever. That is a different subject best left for another day.

Take the time to thoroughly read any information regarding your scope and its controls. I cannot give details here as we don’t have enough space for a book. Many scopes use slightly different turret measurement systems, as well as sub tension designs within the reticle. This is another area where you will have to do some work on your own.

What I will say is, the better the scope the quicker the end result, much of the time.

The Process

adjusting a scope

After a scope has been mounted and tightened up, the next step is to produce a dead-on zero at 100 yards down range. Several methods of proper sighting in will be discussed here, with the first being a bore-sighting system or look-through, depending on the action type your rifle is making use of.

Bore-sighting with a special tool allows the scope to be roughly centered from the bore for more precise adjusting when correcting the scope's elevation and windage settings. The second system of a bolt action design allows the bolt to be removed and the shooter sights directly down the bore.

Without moving the rifle, and still looking at the center of the target directly down the barrel by eye, the diameter and elevation knobs can be corrected to center on the target. I call this method, low ammunition volume sight adjusting.

Windage and elevation knobs

scope adjustments

Another method is to first shoot a round into a close-range target at about 25 yards. If you make a hit that can be seen through the scope, keep the rifle exactly where it was when fired (target center) and, without moving the rifle, turn elevation and windage adjustments one at a time to bring the crosshairs directly in line with the same bullet impact point.

The final method is to simply mount a piece of paper at about 25 yards that is large enough to catch that first round, then adjust your windage and elevation to the center of the target. This will take more bullets, but it is also very effective and shows how accurate your scope is by the amount of movement produced when adjusting to hit the target dead center.

If you can't zero your scope at even 25 yards, check your mounts for tightness. This is a common problem and should be addressed straight away.

scope adjustment knobs

When you have established a 25-yard zero and you are consistently hitting target with your rifle, you can now move to 100 yards. The exact impact point will not be dead center, but very close when using most types of ammo. Making some fine adjustments to elevation, and even to the diameter, will set your sights exactly where they belong.

Today there are other far more advanced methods of zeroing, and even special optics that allow two zero points to be used. This is used in long-range and military applications, and for the most part not by hunters taking game at normal ranges. By establishing a correct 100-yard zero, you're in the driver's seat regarding most requirements of the modern center fire rifle.

Want to know How To Use a Rifle Scope? Check out our guide.

L.P.Brezny has been writing and reviewing products as well as how to projects for the past 50 years. He has authored four books on shooting with three on long range, and one covering shotgunning.(Amazon) With 26 years in a metro police department as a street officer and the rank of SGT / training L.P. has covered all the bases regarding weapons and street survival.

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