Factors in Selecting a Riflescope

Before selecting a riflescope you must have it clear in your mind what the main purpose of the scope is. Many people own more than one scope to handle the various uses to which their rifle may be put. For example, you would not necessarily use the same riflescope for target shooting as you would hunting moving big game.

Even if you have unlimited funds to buy the best,  a high magnification target scope will not be good for hunting small game that might be moving fast.  First and foremost the scope brings the target closer, enabling you to shoot more accurately but not to easily follow moving objects. A good scope will also gather as much light as possible in order to offer good visibility of the target under variable lighting conditions, and enable a hunter for example, to shoot accurately for as many hours in the day as possible. Another factor to consider in your choice is recoil, and the eye relief offered to avoid eye damage through the kick-back.

Let's discuss the major factors to consider when selecting a riflescope taking the comments above into consideration. These are presented in no specific order:

1.  Magnification and Objective

Your scope will be magnification rated in the format 7x32 for example.  The first figure, here the 7, refers to the magnification - the target will appear 7 times larger than it is to the naked eye.  The second refers to the diameter of the objective (front) lens in mm.  The larger this number the more light will get into the scope and the brighter the target will appear.

For hunting large animals such as deer you will need a low-powered variable magnification of 1.5-6x32 for close-range shots such in a forest. If the deer is at medium range, then a medium powered scope at from 2.5-10x50 would be better.  1.5-6x32 might be OK depending on the target distance, though the lower powered magnification is better for moving targets because too high powered a scope won't enable you to keep up with the target properly.

The higher powered variable scopes, such as 6-18x40 or 2.5-10x50 are best for target shooting where there is no movement of the target, or for smaller animals (vermin or varmints, pigeons, squirrels, etc.). 

Too low a power and you will lose accuracy, but too high a power and you will lose the ability to keep up with movement and you will have to keep completely still or use a rest such as a tripod. It is a matter of balancing the usage with the available magnification and objective options. Always use a variable riflescope when you can because you then have the option when needed.

2.   Water and Fog-Proof  

Make sure that your scope is properly sealed and does not allow ingress of moisture.  Most riflescopes are now pretty good in that respect, but taking the time to make sure that your lens won't fog up in adverse weather conditions is worth doing. O-Ring sealing and nitrogen purging are factors to look for, and don't just believe a statement but ask for the proof. 

3.  Lens Coatings

Make sure that your riflescope lens is coated to prevent scratching and glare, and also if possible to improve resolution. Most are, but like water and fog-proofing, you should ask the question and ask to see the evidence.

4.  The Riflescope Reticule

You are offered a good range of reticule options these days, so check these out when selecting a riflescope and choose one that suits you best. Not all reticules are the same for the way you sight, and you might find a difference in accuracy between reticules.

5.  Eye Relief

Eye relief is important for high-powered rifles, and is the distance you can keep the scope away from your eye and still maintain a full field of view. High-powered rifles can have a hard recoil, or kick, and a good eye relief can protect your eyes from recoil damage. Check whether or not the eye lens has a soft covering to further protect your eye.

6.  Riflescope Adjustments

When selecting a riflescope, check out the adjustments that are available. Windage and elevation adjustments should preferably offer an audible click for each step so you don't have to take your eye off the scope for a visual.  A reasonably good riflescope should offer at least ¼ M.O.A. (Minute Of Adjustment) which means ¼ inch adjustment for each 100 yards. This translates proportionately at other distances, so it is equal to ½ inch at 200 yards and 1/8 inch at 50 yards.

7. Mounting

For best accuracy the riflescope should be mounted as closely as possible to the barrel. This means a compromise between the objective and the mounting, because large lenses cannot be situated close to the barrel! A good compromise for you if need a large objective lens is 40 - 44 mm.

Finally:

When selecting a riflescope pay attention to its manufacture, mechanics and strength. The scope has moving parts and sensitive lenses, and a well-built scope will help prevent inaccuracies through the effects of recoil. By checking each of the above factors you can be certain that you have done the best you can in selecting a riflescope to meet your needs as completely as possible and offer you the greatest possible accuracy in your shot.