It used to be that, when choosing a riflescope, the most complicated decision you needed to make was whether you wanted fixed power or variable power.
Today, you not only have choices between fixed and variable, but also about what range of powers to choose, how to mount the scope to your rifle, what the crosshairs (reticle) look like, if you want the reticle to light up and if you want range estimation features built in.
FIXED OR VARIABLE POWER
Scopes come in one of two basic configurations: fixed power, with which you only have one magnification level, or variable power, via which you can move back and forth between a lower power and a higher power, depending on your needs.
Fixed power scopes are best when the range in which you are aiming only varies by 100 yards or so. If you only take shots under 100 yards, only shoot across crop fields or only take long-range shots more than 500 yards, get a fixed power scope for each distance and put it on the rifle that works best at those ranges. Because they also have fewer moving parts, the chance of something failing on fixed scopes is minimal.
WHEN I WAS FIRST LOOKING AT RIFLE SCOPES, ONE OF THE THINGS THAT BECAME APPARENT IS THAT THERE ARE TWO DEFINITE CAMPS WHEN IT COMES TO ADJUSTING SIGHTS.
Variable power scopes give you the flexibility to use one scope for a variety of ranges and uses. For example, with a 3-9×35 scope, you would use lower powers for hunting in brush or woods and higher powers for taking a long-range shot across a field or canyon.
The magnification level is shown, along with the size of the objective lens. So, a fixed four-power scope with a 30mm objective lens would be a 4×30. A scope with variable power from seven to 12 with a 50mm objective lens would be a 7-12×50.
RETICLES, RETICLES AND MORE RETICLES
The reticle is the image you see when you look through the scope. In its earliest forms, it was either an aiming dot in the center of the scope or a set of horizontal and vertical crosshairs. Today, reticles come in a wide variety of designs, each with a specific purpose. The major categories are described below.
Crosshairs: Regular crosshair reticles are great for anytime you would need a scope, whether it is for target shooting, hunting or self-defense. They not only provide a precise aiming point to use, but with the right angles of the crosshairs, they help you ensure your scope is level.
Duplex: The difference between standard crosshairs and duplex crosshairs is that the outer ends of two or more of the crosshairs are thicker than the crosshairs in the center. The thicker lines make it easier to get a quick sight picture.
Ranging: Horizontal lines along the vertical axis of these crosshairs help you determine the correct holdover for different ranges. In most cases, they are set at approximate 100-yard intervals. The trick is to know what each line represents for your gun and the ammunition you are shooting, because it can change with each type of ammo. These reticles are best used if you know the distance to what you are shooting at.
Mil-Dot and MOA: These are the other kind of ranging reticles. In this case, you use the dots on the vertical and horizontal crosshairs to help determine distance, windage and holdover. If you know how wide or tall something is, you can also estimate distance. For example, you know that something is 2 meters wide and that the distance between two of the dots on your reticle is 1 meter at 100 meters. If the object spans two dots, it is 100 meters away. If it spanned one dot, it would be 200 meters away.
BDC: Ballistic or bullet drop compensation (BDC) reticles are similar to ranging reticles in that they have horizontal lines showing holdover for different ranges, but the distance between the lines is based on the ballistic characteristics of a commonly used round. This makes them useful for a large percentage of users—but not if you don’t shoot a round with the same ballistic properties.
CQB or CQC: Close-quarter battle (CQB) or close-quarter combat (CQC) reticles are a mix of ranging crosshairs and a thick circle or semi-circle intended to make it easier to get on target at distances from 1 to 50 yards. Some like the thick circle for this purpose, while others think it blocks their view of the target and what is going on around it. I tend to agree with the second group and prefer a ranging reticle with an illuminated center dot for quick target acquisition.
MIL OR MOA
When I was first looking at rifle scopes, one of the things that became apparent is that there are two definite camps when it comes to adjusting sights. One camp prefers milliradians, or mils, and the other prefers minutes of angle, or MOA.
One milliradian is 1/6,400 of a circle. One minute of angle is 1/21,600 of a circle. Milliradians are based on metric units; minutes of angle are based on English units.
Fortunately, you can boil it all down to a few key points that make it easy to choose what you use. Mils and MOA are both units of measure for an angle, and the width of that angle will always be a factor of some multiplier times the distance. You just need to know how much the one you picked is at key distances such as 100 or 1,000 units.
The main difference is that 1 MOA is a narrower angle than 1 mil. Most adjustments are done in ¼ MOA or 1/10 mil, but the difference between the two at 1,000 yards is only 1 inch. One click on the MOA scale is 2.6 inches, while one click on the mil scale is 3.6 inches.
The key to keeping things as simple and consistent as possible is to make sure you use the same option on both of your turrets.
FFP OR SFP
For our use, the focal plane refers to which lens in the scope has the reticle on it. The first focal plane (FFP) is at the objective (target) end of the scope, and the second focal plane (SFP) is at the ocular (eye) end of the scope.
This only matters if you are using a variable power scope, because it affects the position of the ranging aids, dots and stadia lines on your reticle.
The key to remembering how the focal plane affects what you see in the scope is that in FFP scopes, the size of the reticle grows with the size of the image. This means that the position of the dots and stadia marks on your reticle stay in the same relative position for whatever you are looking at, such as right behind the shoulder on a big, mature buck or the center of the gas tank of the car you are trying to disable.
With SFP scopes, the reticle size remains constant. This means that as you zoom in on your target, the reticle grows narrower in relation to what you are looking at. This is better if you are looking for detail on your target or want to make a very precise shot.
If you plan to use the dots and stadia metric marks on your scope’s reticle to adjust for distance and windage, choosing an FFP scope will allow you to do that at any magnification … if you use a variable power scope.
We have covered a lot of information, and I am sure you have a lot to think about in terms of what kind of scope to get for your particular purposes. However, I would like to offer a few pieces of advice:
Choose the least cluttered reticle that still meets your needs.
If you think in metric units, go with a mil reticle. If you think in yards and feet, go with an MOA reticle. Just make sure both turrets use the same units.
If you are going to use your scope and reticle for range estimation, go with a first focal plane scope; if not, a second focal plane scope will work just fine.
If you can afford it, go with an illuminated reticle so you can aim with it in any light conditions.
RETICLE TERMS
BALLISTIC DROP COMPENSATOR (BDC): A reticle pattern with tick marks that show elevation for a specific type of ammunition based on its caliber, bullet weight and velocity
FIRST FOCAL PLANE (FFP): The objective lens in your scope
MIL-DOT: A type of reticle with dots set apart at predefined milliradian distances to aid in determining distance and in adjusting your aiming point
MILLIRADIAN (MIL): An angular measure, often called a “mil.” It is equal to 1/6,400 of a circle.
MINUTE OF ANGLE (MOA): An angular measure, often called an “MOA.” It is equal to 1/21,600 of a circle.
OBJECTIVE LENS: The lens farthest away from the shooter and closest to the target
OCULAR LENS: The lens closest to the shooter and farthest away from the target
RETICLE: The crosshairs or other image the shooter sees when looking through the scope. Reticles come in a variety of designs, and each has a specific purpose.
SECOND FOCAL PLANE (SFP): The ocular lens in your scope
TURRET: The round knobs on the outside of the scope body for adjusting windage and elevation
Editor’s note: A version of this article first appeared in the March 2017 print issue of American Survival Guide.