Understanding and Selecting Firearm Optics

How to Avoid the Common Mistakes

Why Use Optical Sighting Devices with your Firearms.

These days, most firearm enthusiasts use some kind of optical sighting device on most of their guns. Not just rifles, but shotguns and handguns as well.

There’s a great reason for this. Simplicity. Aiming through a scope or a red dot sight completely eliminates one third of the complexity of lining up iron sights. With metallic sights you are required to line up the rear sight with the front sight and your target. With a scope, you simply have to line up your crosshairs (reticle) with your target making it much easier to learn to shoot with a scope than iron sights. Since most rifle scopes also magnify, your target appears closer and therefore easier to see, enabling you to place a more precise shot on your target. People with less than perfect vision are able to adjust the reticle focus at the eyepiece (ocular) for a clear, crisp reticle and by adjusting the parallax turret a crisp, clear sight picture.

When buying a new telescopic sight, it is best to start with a clean slate. There are many things to consider and there is no one type of scope that is good for every gun. Just because your friend has a 3-9×40 on his hunting rifle does not automatically make it the best scope for your hunting rifle.

Here are a few tips…Buy the best scope you can afford for the gun.

Unless you try to use your riflescope as a spotting scope, or you are a serious target shooter, you are unlikely to notice large differences in optical quality just by looking through a scope. The most important reasons for buying a more expensive scope are not that obviously visible. The most important virtues of a telescopic sight are reliability and retaining a zero. Modern manufacturing techniques have made today’s scopes cheaper, more reliable, and with better lens coatings than what was ever possible before. Many of the new (better) scopes became available after the invention of computer optical design programs.

Don’t Buy Old Technology. Don’t buy a particular scope just because your friend has one or your uncle had one. For hunting there is a wide range of possibilities when it comes to selecting the best scope for your rifle. Lets look at a few generalizations and go from there. The point is, that you need to match the scope to the type of shooting you will most often be doing, and the rifle to which it will be mounted. Many people get it wrong. They automatically want to put a 3-9×40 on their deer rifle and a fixed 4 power scope on their 22lr. Why…when rabbits are smaller than deer and are frequently seen at equal or greater ranges than deer.

Lets look at 22s and Scopes for Small Game. Most 22s are used for small game. Sitting side on at 75 meters a rabbit presents a target roughly the size of a red brick. The instant kill area is smaller than a business card. On small game, without a scope very often you can only see their eyes. A bit of magnification helps to see the body and avoid twigs and branches, important since small game will usually remain still for only a few seconds. Most people only want to buy a fixed 4x power, but we usually recommend a 3-9×40 as the best all-round scope on a 22lr for most uses. In many brands the difference in price between fixed and variable power scopes is usually negligible.

Scopes for Medium-Sized Game Hunting with a Rifle

Most people by far ask for a 3-9×40 scope on their deer rifle. If a rabbit has a kill area the size of a credit card, a deer has one the size of a dinner plate. A much bigger target than a rabbit, deer are frequently seen at 5 to 25 meters and often on the move.  Even at 200meters a dinner plate is a reasonable target, well achievable with a 5x power scope. That is the equivalent of the same plate at 40 meters with no magnification. Although a 3-9x is more than adequate for most deer hunting it lacks sufficient field of view for close running shots. Therefore we recommend a 1.5-5x, or up to 2-7x for most deer rifles. The small front lens diameter is not a disadvantage as its field of view and light gathering capability are both greater at lower magnification.

Exceptions where a bigger scope might be appropriate are when the rifle is used principally on larger game; then consider a 3.5-10 or 4-14 power.

Scopes for Varmint Rifles

Varmint rifle (Wikipedia definition) is an American English term for a small-caliber firearm or high-powered air gun primarily used for varmint hunting — killing non-native or non-game animals such as rats, house sparrows, starling, crows, ground squirrels, gophers, jackrabbits, nutria, marmots, groundhogs, porcupine, opossum, coyote, skunks …

Here we are looking at even smaller kill zones-and distances maybe 100, 200 or even 300 meters. Any takers for the 3-9x? In this area, more is better. Trade the light gathering for pure magnification. You need it. Ignore scopes with very fine crosshair only reticles. You cant see them in hunting situations where there is no white paper target to aim at. Pick a standard or fine 30/30 or Plex type reticle and buy the most expensive one you can afford. In varmint scopes, cost equals quality. In fact a good scope can cost more than the gun. Avoid powerful fixed power scopes, as they wont let you take a 25m shot. Use a front lens shade and invest in a laser rangefinder and a bipod. Oh, and a broad stretchy sling to save your shoulder when you have to carry it all.

As you start to shoot your varmint rifle you will start to grow into the more powerful varmint scope. You will actually see your heartbeat bouncing the cross hairs at anything more than a 16x power setting. But, amazingly, after a few months you will learn to shoot between the heart beats (truly) and then you will start to use the top end of your scope’s magnification range. Trust me… a small game bird at even 200m is a mighty small target. Don’t put a 3-9x on your Varmint rifle. If you’re into the Long Range Hunting or Extended Long Range Shooting, I highly recommend the Tremor or the Horus H59 Reticle both First Focal Plane Reticle. 

Variable v/s Fixed Power Scopes

The reasons for not buying variable scopes used to be that they were more expensive, had lower quality optics and fogged more often. None of these things remain true at this time. In many cases a variable power scope is the same price or less than a similar fixed power scope. The scope manufacturers make so many variable powered scopes that the unit manufacturing cost is now much lower. Once again, purchase the type of scope to fit the gun and the purpose of use.

Eye relief is the distance that you hold your eye from the back of the scope. Features of eye relief are the distance required to see a clear full picture through the scope, and sufficient distance to protect you from “Weatherby, Magnum Eyebrow or Scope Kiss”—a bruise injury from a powerfully recoiling rifle. Recoil management is important to prevent this injury. Important when in a Prone Position to use the “Superman Positioning” to manage the recoil.

• Generous Eye relief means that you can move your eye back and forward perhaps an inch or two (25-56mm) and still see the target clearly.
• Shallow eye relief means there is only one right spot. Scopes like this are not good for quick or running shots since it is difficult to find the precise spot on the run. 

Scope Turrets cover the adjustment dials, usually in the Top middle of the scope.

• Target Turrets may be tall, and some may not even have screw-on caps to cover them.
• Hunting Turrets are small (not tall) and ideally should have clearly defined click-stops in their adjustment.
• Click stops- Most common for Mil Turrets are 10 clicks per mil, which is 3.6″ of elevation at 100 yards. Most common for MOA Turrets are 4 clicks per MOA which is 1.047″ of elevation at 100 yards. Whats really important is that your turret matches your reticle. If you have mil turrets make sure the optic has a matching mil reticle. The same goes if you have an MOA turret that your reticle is also MOA. It makes the math a lot easier when you’re doing the calculations.

Scope mounts. There is a bewildering range of options to choose from when selecting scope mounts. The average is in the price range from $50. to $500. It is always to your advantage to buy the best scope mounts that you can afford. I recommend One Piece QD scope mounts which would cost around  $300. There is less error when attaching your optics to the mount and when removing the optic from the rifle. Also when reattaching the optic and mount back to the rifle, if placed exactly in the same location on the rifle- these mounts will retain the original Zero. LaRue makes great mounts.

Understanding Parallax

Telescopic sights are manufactured to be parallax-free at a particular distance. At the stated distance, you can move your eye around behind the scope and the crosshairs do not wander on the target. This distance is usually 100yds, but some special scopes are focused at closer or greater ranges. It is more noticeable on very powerful magnification scopes; so most riflescopes more powerful than 10x power have a ring on the front (or a third knob on the turret) for dialing the correct parallax. Parallax is a big deal and you need to make adjustment to remove it especially for Long Range Shooting.

Light gathering is the ability of your scope to gather all available light from a target and transmit it through the scope to you eye. The larger the front lens or tube diameter, the more light than can be brought to your eye.

Magnification. Riflescopes are usually referred to by their magnification power and the diameter in millimeters of the front (objective) lens. i.e. a 4×40, 1.75-5×32 or 4-16×44.

One of my favorite optics for Carbine is the ACOG which stands for Advanced Combat Optical Gunsights (abbreviated ACOG). They are a series of telescopic sights manufactured by Trijicon. The ACOG was originally designed for use on the M16 rifle and M4 carbine, but Trijicon have also developed ACOG accessories for other firearms. Models provide fixed power magnification levels from 1.5x to 6x. ACOG reticles are illuminated at night by an internal phosphor. Some versions have an additional daytime reticle illumination via a passive external fiber optic light pipe or are LED-illuminated using a battery.

The ACOG is available in a variety of configurations from the manufacturer with different reticles, illumination, and other features. Most ACOGs do not use batteries for reticle illumination. What I like about the ACOG is that it is very quick to acquire your target. You keep both eyes open. This overcomes the problem of centering or acquiring fast traversing targets common with all telescopic sights. Only certain models of the ACOG are designed with bright-enough daylight-lit fiber-optic or battery-powered LED reticles that facilitate this technique. Most ACOG models are designed for use with the “Bindon Aiming Concept“, an aiming technique developed by Trijicon founder and optical designer Glyn Bindon.

A couple of my personal favorite scopes for Extended LONG RANGE SHOOTING is the NightForce ATACR  5-25×56 F1 or for ultra long range 7-35×56 F1 and the Schmidt & Bender PM High Power 3-27×56 F1. NightForce & Schmidt & Bender are by far some of the best scopes on the planet. Also another great Long Range Scope at an affordable price tag is the Bushnell XRS 2 Elite Tactical 4.5-30×50 F1, all with the TreMor 3 or  H59 Reticle. Hope this information helps you decide on whats best for you!