What To Look For When Buying A Rifle Scope

Nowadays it is hard to imagine a rifle without scope. Rifle scopes can help you to uncover the potential of your weapon in the best way. It is very important to choose the right one. Below you’ll find 10 helpful tips that you should consider when choosing a rifle scope.

Rule of Thumb

A scope for an accurate and reliable rifle should cost at least half of its price. Cheap scopes are not able to uncover rifle’s potential. Of course they are less reliable too.

Lenses are the main ingredient

Lenses form the image. Everything is simple here – you get what you pay for. Premium rifle scopes of well known manufacturers have the best lens’s quality. Their lenses go through a number of manipulations and tests before get in the rifle scope. Cheap scopes are more affordable but image quality is significantly lower. Such manufacturers as Leupold, Redfield, Nikon, Zeiss, Burris, Bushnell, Trijicon are well known in rifle scope production. You cannot afford to buy quality precise rifle and a cheap scope. It’s just not going to work. Spend as much money on the scope as you can, but never less than half of the rifle’s cost.

Lens quality and its coating determine the light transmission. Most expensive scopes have 98% light transmission. Majority of the rifle scopes have light transmission in the range of 90% to 95%.

Magnification is very important

The 3-9x is standard for whitetail deer hunting. The 4-12x or 4.5-14x is good for antelope or mule deer in Western states. The 6-20x or 8-25x are very good for varmint hunting or target shooters. Magnification can be fixed or variable. Variable scopes are adjustable via power ring. Fixed scopes have single magnification. The wider is magnification range the more tasks you can accomplish with such scope, the more expensive it is. Fixed scopes are inexpensive and more reliable because they contain less moving parts. The image is clearer in such scopes because of fewer amounts of lenses. However variable scopes of leading manufacturers have very high quality and clear image.

Conclusion: if you are not going to use all magnification range it is better to buy fixed scope. If you need flexibility then do not spare money for a good rifle scope.

Size of Objective Lense

Another important characteristic is the size of the objective lense. The larger objective lens, the larger exit pupil and the better light transmission are. On other hand such scopes are heavier and mount higher that makes them less comfortable for shooting. If you shoot at the low light condition then consider to buy a scope with large objective lens. For the day light shooting 33-40 mm objective lens is just fine.

Exit pupil

Exit Pupil is the small beam of light that you see at the ocular lens. This is the actual image that comes out the scope. The formula for the exit pupil size is simple: Exit Pupil = Objective Lens Diameter in mm/ Magnification. The larger exit pupil – the easier it will be to use such rifle scope. To untrained shooter 7mm or more is a perfect size. While 1.5mm exit pupil creates difficulties even for experienced shooter.

Exit pupil is larger at low magnification and smaller at high magnification. In order to see an image your eye’s pupil should much exit pupil. That is why at the dusk it is hard to use rifle scope on highest magnification. Exit pupil becomes thinner and your eye’s pupil extends.

The larger exit pupil the larger eye relief is. Eye relief is the distance between scope’s ocular and your eye. The 3.5 to 4 inches eye relief is common for most standard rifle scopes. It is enough to prevent you from “black eye”.

Conclusion: since almost all scopes are variable the size of objective lens is the characteristic that determines exit pupil size. Scopes with small objective lens are lighter but harder in use. Rifle scopes with large objective lens allow you to use it on highest magnification at lowlight conditions.

Field of view

The field of view (FOV) is another characteristic that you should consider when choosing a rifle scope. This is basically the width of the picture that you see through the rifle scope. It measures in degrees or feet at the 100 yards.

The thing you should know about FOV is that larger objective lens DOES NOT make field of view wider. This characteristic completely depends on the rifle scope’s design.

The main tube

The main tube is the tube between ocular and objective bells. It can be made from multiple or single pieces. The fewer pieces the more durable rifle scope is. Expensive scopes usually have a solid main tube. Tubes of inexpensive scopes can be made from two or three pieces.

There are tubes of different diameter. Most popular are 1” (25.5mm) and 30mm main tubes. The larger tube the greater range of elevation and windage adjustments is. Note: larger tube DOES NOT mean more light transmission. Light transmission completely depends on lens quality and coating.

Movement

When you move your head aside from the rifle scope, reticle should stay on target all the time. If reticle moves in the relation to the target then it is not in the rifle scope’s focus. This phenomenon is called parallax. In such case you should adjust parallax or in other words focus your scope.

The parallax adjustment (focus) system can be at the objective (adjustable objective), on the side of the rifle scope (side focus) or at the ocular bell. More comfortable and precise is the side focus system.

If rifle scope does not equipped with parallax adjustment system it is focused at the distance of 100 or 150 yards. Then you should find a note that this scope is “100 or 150 yards parallax free”.

Elevation and windage

Another thing you should take a look at when choosing rifle scope is elevation and windage adjustment system and its range. The simplest scopes feature infrequent adjustments using screw driver or coin, while tactical scopes with large turrets allow you to make adjustments at the field.

Most popular are adjustments in minutes of angle (MOA) with ¼ MOA increments. Some tactical rifle scopes have adjustments in mil radian to match mil radian based reticles. As I said earlier the largest main tubes allow wider adjustment range.

Reticle

Last and probably the most important feature in choosing a rifle scope is the reticle. It determines rifle scope’s usability. The Reticle helps you to aim, determine distance to the target (mil or MOA based), holdover for the bullet drop and crosswind (ballistic reticles) and more. There is great variety of reticles. Most popular are Duplex and its variations.

For running targets or boar hunting consider heavy and obvious reticle. Such reticles will quickly lead your eye to the center. For a big game hunting at 100 – 200 yards Duplex and its variations (Plex, Z-Plex, 30/30 and so on) are just fine. For the long range shooting or varmint hunting you should take a look at the ballistic reticles. For those who hunt in the low light conditions different illuminated reticles might be helpful.

Reticle can be located at the front (first) focal plane (FFP) or at the rear (second) focal plane (RFP or SFP). If reticle located at FFP it magnifies along with the target, so you can use it to measure the distance or for hold over at any magnification. However at the low magnification such reticle is too small and you are not able to use its features.

These tips should help you with your rifle scope purchase and decision. If you have any questions or comments, leave them below.