How To Adjust A Rifle Scope

adjusting a rifle scope

If you are new to hunting with a rifle scope, you need to know how to adjust a new rifle scope. Scope adjustments are not complicated. Scope adjustments are the same for most scopes, modern holographic or red dot scopes and thermal or night vision scopes.

If you can recall your geometry lessons or even the cardinal directions on a map, then you can understand how the scope's internal sighting mechanism moves. You go up, down, left and right. There is no backward or forward for the dot or crosshairs reticle. Backward and forward adjustments move the entire scope along the rail that attaches it to the gun.

For more than 40 years, I have chased animals and shot targets across the United States and Canada. I have hunted with and without scopes. I prefer scopes on my rifles and shotguns when I shoot slugs. Over the years, I have shot high-quality scopes and scopes that went in the trash as fast as I could remove them. Here are some lessons I learned about how to adjust a rifle scope.

Mounting The Rifle Scope

scope adjust

Once you choose a rifle scope, you then have to choose a rail. How you adjust a rifle scope starts with mounting the scope to the rail. Optics Planet has a video walking you through the process. 

If you have a tube-style rifle scope, you have to pick rings. Holographic, reflex and red dot sights do not need rings. Some rifle scopes do not need a rail as they come with a mounting system.

Height Adjustment

scope adjustment

Rings, on a tube scope, are what holds the scope in place. They also provide elevation adjustments. The most common rings are 1-inch. Other sizes are:

• 30 mm, the second most common

• 34 mm, the third most common, but still uncommon

• 35 mm

• 36 mm

• 40 mm

Some special application scopes will have special rings meant only for that scope.

Rings also come in various heights for elevation adjustments. You can get low, medium, high and very high. Rings raise the scope above the barrel.

Very high rings are the choice for long-distance shooters.

Lateral Adjustment

Ring placement matters for scope focusing and not smashing your eye. "Eye relief is the distance between the lens of your binoculars or scope to the tip of your eye. When viewing a scene through any lens with incorrect eye relief distance, the picture you see will be distorted, either with a fuzzy image or with a black ring around the field of view," says scope maker Bushnell.

how to adjust a rifle scope

You move the scope backward and forward in the rings until you get a clear sight picture through the objective lens and the gun is comfortable to hold against your shoulder as you look through the scope. Fuzzy means you are too close. A black ring means it is too far away.

Scope alignment in the rings is critical. This means your scope is mounted straight on the rail and in the rings. A scope alignment kit will make sure your scope is not twisted in the rings and mount. A twisted scope will be hard to zero and hard to keep in zero.

Rails

rifle scope adjustment

Rails come in two types, Picatinny, also known as pic, and Weaver. The main difference between the two is the pic rail has standard, even spacing on the top. The bars and gaps between them are always the same no matter who makes the rail.

A Weaver rail can have a center groove and can have bars and gaps that are widely spaced. Weaver rails are not the same from maker to maker. The ring mounting space between two rails on a Weaver scope is the same as the spaces in a pic rail.

Pic rails are more common than Weaver rails.

A few rails and rings have specialty mounts. These are found on high-end scopes, rings and rails. You can move the scope rings backward and forward on the rail for eye relief adjustment.

Leveling The Scope

adjusting scope

You need to make sure the scope is mounted level on the rifle. A simple spirit level makes sure the rifle is level and then the scope is level. 

Sighting In

Once you get the scope mounted to the gun and comfortable on your shoulder, it is time to move to sighting in your scope. The sight-in process moves the reticle alignment up, down, right and left. A typical tube scope has two adjustment knobs, called turrets. One is on the top and one is on the right side.

how to adjust a scope

Some red dot and holographic sights also give you a choice of sight. It can be a dot, a dot in a circle, crosshairs or crosshairs with a dot in the middle. A few of these scope makers have fun with the reticle. The AIM Sports Warfare Edition has a smiley face, Predator triangle, double arrow and dot and a skull reticle.

Bore Sighting

Before you shoot, save some time and money by bore sighting your rifle. Bore sights are inexpensive. This will probably not zero your rifle. If it does, that is a rare thing. It should get your first shots somewhere on a good target if you are shooting 50-100 yards. Then you make the fine-tuning adjustments.

Time To Shoot

how to use rifle scope

Now it is time to shoot. Most people use a rest or brace to support the gun and hold it steady when shooting. I have used a rolled-up jacket in the past. Other braces are sandbags, either homemade or commercial gun rests. The best support which allows you to zero with just a few shots is the Caldwell Lead Sled. With weights added to it, the Sled also tames the recoil of the biggest of the big bores.

Carefully shoot the target, aiming at the dead center. The Texas Department of Wildlife has an excellent article and videos on proper shooting techniques.

Some shooters say shoot three times. Some say shoot once. A three-shot group tells you where the bullet is hitting and eliminates flyers.

Now you have a choice. 

• If your eyes are good enough (I am old and my eyes are not good), you can see where the bullets hit the target from your shooting position. 

• You can get highlighting targets that are visible at a distance, even for an old shooter like me.

• You can use a spotting scope or binoculars to see the holes from where you shoot.

• You can go down to the target and see where the bullet hit. I usually do this.

If you do not find a bullet hole, cut the distance between you and the target in half. Repeat the check above. At 25 yards, you should be on the paper with a shot. If you are not, then something is wrong with the gun, the scope, how you are shooting or your ammunition. 

Have someone else shoot the gun to eliminate shooter error. We once had a great time on a range by giving a good friend some ammo loaded with disintegrating rounds. He was finally about three yards from the target before he discovered our joke. The paper was peppered with fragments.

Once you get on target, start making adjustments.

Precision Adjustment

adjusting a scope

Elevation adjustment is or up and down and windage adjustments are right and left. You will remove the caps from the turrets to make these changes. You can make windage adjustments with your fingers on some scopes. On other scopes, you may need a dime or a penny to put into the windage adjustment or elevation adjustment slot to turn it.

As change the windage adjustment, refer to the scope's manual. The most common adjustment in tube scopes 1/4 Minute of Angle (MOA).

Some tube's scope adjustment is in Miliradians (Milrad). Guns & Ammo discusses scope adjustment in MOA v. Milrad in this article.

The most important part is how much each click of the knob in the turret moves the sight. The click or click value is an audible "click" or something you can feel as you move the adjustment knob.

Some scope mounts offer a rough windage adjustment. Use this when your scope is so far out of alignment the internal adjustments are not enough. If you do this ring adjustment, you need to make sure your scope stays in proper alignment.

MOA

set the scope

MOA - At 100 yards, an MOA is roughly equal to one inch. The actual value is 1.047 inches. For most shooters, this is not important. It is important for shooters reaching out to 1,000 yards and more.

A 1/4 MOA adjustment means the sight moves 1/4 of an inch at 100 yards. So, if you are off by one inch at 100 yards, you need four clicks to zero at 100 yards. If you are off by two inches, you need eight clicks.

MILRAD

how to adjust rifle scope

A milrad is 3.6 inches at 100 yards. At 1,000 yards it is 1000 yards. The most common adjustment is 1/10th of a milrad or one centimeter at 100 meters. That is very close to 1/4 of an MOA at 100 yards.

If you are off an inch at 100 yards with a Milrad scope, you need four clicks in the correct direction.

Elevation

Elevation is the up and down movement of the crosshairs or the dot, whatever the scope uses to mark the target. The same measurements on elevation apply to windage.

After you shoot, take the cap off the top turret. Adjust the knob up or down, depending on where the bullet or the group hit the target.

Windage

windage adjustment

Windage is the left and right adjustment. It is found on the right turret. Remove the cap. If your bullet is hitting left of where you aim, look at the windage turret and adjust to the right. If it is hitting to the right, you need to adjust to the left.

Parallax

adjusting rifle scope

Tactical, long-range and high-end scopes will have a turret on the left side for parallax adjustment and sometimes focus. You need your reticle in the same

Adjusting the parallax increases in importance as the distance between you and your target grows. You need know your reticle is centered on the target. The parallax knob has marks to show you where to dial it to.

Focus

scope adjustments

Some scopes have a general focus ring on the tube or combined with the parallax adjustments. Twist this ring until your target comes into sharp focus.

Most tube scopes also come with a zoom ring so you can adjust magnification.

Some scopes have a lighted reticle. The most common color is red, followed by green. If you have a lighted reticle, the scope also has a way to adjust the light intensity. Reflex and red dots have a knob you twist to change it. Sometimes you can even change colors.

Multiple Shots

It will likely take you several shots to get the bullet to hit the center of the target. This is normal.

how to adjust a scope on a rifle

You should also let the barrel cool down after shooting a few times. As the barrel heats up, it loses some accuracy. You can tell when you need to cool down because the bullet groups start getting larger.

Where To Set Zero

how to zero scope

One of the biggest questions new shooters have is where to set the zero. There is no one answer to this. It depends on two major factors.

1) Your need. How far is your typical target? I've hunted deer across the Southeast and rarely have a shot of more than 100 yards. Most of the deer I kill are 75 yards or closer. The hogs are usually closer. If you shoot much farther away, you need to sight your rifle in accordingly.

2) The gun. Ballstics, how a bullet performs over distance, vary by barrel length and by the caliber. Longer barrels provide more velocity and a longer reach. A .22 has nowhere near the reach of the .300 Winchester Short Mag which now holds the world record group at 1,000 yards.

Some guns like the venerable .30-30 carbine are short-range guns. Sight this gun in at 100 yards and you can expect to hit a deer-sized target out to 150 yards. Check out Gun Data's .30-30 ballistics chart to see how much the bullet drops. The .300 WSM can be sighted in out to 1,000 yards or more.

To see how much a bullet from a given gun will drop, check out the North American Whitetail bullet drop estimator.

As you see, choosing your zero point matters. Just as a rough guide, I sight my .30-06 and .270 in 2 inches high at 100 yards. With that, I know I can center the crosshairs on a deer at anywhere out to about 250 yards. If I do my part, I know I have a solid hit on the deer. I sight my .45-70 Government carbine in at 50 yards. I'm good out to 100 yards. I sight my .22 rifles in at 25, 50 and 75 yards, depending on the gun. My .204 Ruger is sighted in 2 inches high at 100 yards. I know I can whack a coyote out to 300 yards with just a bit of holdover. Holdover means I set the crosshairs above the place I want the bullet to hit. Holdover varies by gun, projectile weight and distance.

I sight my .45-70 Government carbine in at 50 yards. I'm good out to 100 yards. I sight my .22 rifles in at 25, 50 and 75 yards, depending on the gun. My .204 Ruger is sighted in 2 inches high at 100 yards. I know I can whack a coyote out to 300 yards with just a bit of holdover. Holdover means I set the crosshairs above the place I want the bullet to hit. Holdover varies by gun, projectile weight and distance.

Focal Plane Scope

how to adjust scope

Scopes are first or second focal plane. First focal plane means as you zoom in, the crosshairs get bigger. Second focal plane scopes means the reticle stays the same size. Reflex and red dots are not focal plane scopes.

Advanced

If you get into long-range and precision shooting, you will invest in a rifle scope with fingertip adjustments and a return-to-zero feature.

scope adjustment knobs

You sight the scope in with the turrets. Then you gently pull the turret cap up and twist it to make the zero line on the cap meet the zero line on the turret tube. The cap will not come off. It is designed to be pulled up and turned.

When you are in the field shooting, you gently turn the turret cap. It moves the crosshairs to the left or right on the windage turret. The same action on the top turret moves the crosshairs up and down on the elevation turret.

Expert shooters know how to "dial in" their scopes for distance and wind conditions. You do not have time to re-sight in your scope. Instead, you rely on your knowledge of the gun, bullet performance and the scope's ability to adjust on the spot to account for different shooting conditions.

Of these two adjustments, windage is the most difficult to account for when shooting in the field. Bullet drop is fairly consistent once you learn it. The National Sports Shooting Foundation has some tips on how to read the wind.

Go Shoot Already

how to use a scope for long range shooting

Once you get things sighted in, go shoot already. With a good rifle, good ammo and a good scope, you are the determining factor for accuracy. The more you shoot, the better you will get.

The National Rifle Association's Shooting Sports USA says the best shooters shoot "90,000 to 150,000 practice rounds every year coupled with hundreds of hours of dry firing and practicing, draw, movement and reload drills—they wear out guns just dry firing! A top SASS shooter will burn 100 pounds of powder practicing in one season."

That is a lot of ammo, and probably out of reach of the average shooter. You should commit to shooting a few boxes of ammo every month. One great thing and a bad thing at the same time is shooting habits are in you, not the gun. The same way you shoot a .22 rifle will translate directly across to how you shoot a .243 or a .270. If you shoot badly with the .22, you will shoot badly with your deer rifle.

Shooting more, under a variety of conditions and distances, also means you learn how to adjust for wind and distance. The particular scope you chose matters less than how much you practice.

Leave a Reply

Your email address will not be published. Required fields are marked *