The rifle scope is designed to magnify the user’s eyesight, allowing the long-range marksman see distant targets up close. A scope with a magnification of 20x (power) would allow you to see a target 20 times larger and closer. A target ranged at 1000 yards would appear to be 50 yards from you. In the hunting field, targets are identified with binoculars first, and then seen with the rifle scope. Safety is enhanced by clearly seeing the target and beyond, shooting only the intended target. At the shooting range, the bullet holes can be seen at further distances (100-300 yards), giving the shooter the ability to see point of aim and bullet impact.
The perfect long-range rifle scope will have “variable” magnification power. The most common variable power scope is the 3x-9x power scope. The low, 3 power setting allows for the up close shots (dark timber) while the high setting of 9 power, allows for longer shots of 300 to 500 yards. For those interested in shooting out to 1000+ yards; the variable power scopes of 3x-17x, 4x-12x, 4.5x-14x, 6x-18x, 5.5x-22x and the 6.5x-20x power is appropriate.
The objective lens of the long-range scope should be no smaller than 40mm (millimeters) and no larger than 56mm with 44mm or 50mm size being the optimal objective lens size. The 44mm objective will allow you to mount the scope low on the rifle, without the objective end of the scope touching the barrel. Low scope mount is desirable, because of consistent cheek placement on the stock (cheek weld), giving you a more natural point of aim as you look through the scope. Get the scope with the adjustable objective(AO) or side focus. This will allow you to focus at extended distances to adjust for a condition called parallax. When viewing distant targets the image and the cross-hairs (reticle) appear to shift and get shadows in the sight picture. You can turn the knob on the objective end of the scope (or on the side turret) and focus clearly on the distant target.
In order to make “Hits” out to 1000 Yards or more, the Scope you choose must have “Target Knobs” for the Elevation and Windage Dials. Also these Knobs must have alot of “Internal Adjustment” 120+ clicks and/or 50 MOA Elevation, and those clicks must be solid. The Scope must have the ability to return to it’s Zero, time and time again, when the knobs are turned in the field.
The field of view (FOV) is the left to right; side to side view you see as you look through your scope and is usually measured in feet at 100 yards. As the magnification of the scope is increased (higher power), the FOV goes down. And when the scope is adjusted to the lower power setting, the FOV goes up. The wider the field of view the easier it is to find or acquire the target in the scope. Again targets are spotted with binoculars first, so there will be time to find the target in the scope.
Most game animals are spotted during low light levels such as early morning and late evening. A quality rifle scope must be able to gather the available light through its objective lens and deliver a clear, sharp, identifiable picture to the eye of the shooter.
The performance of a quality scope in low light conditions is due to the size or amount of light that reaches the pupil of your eye; this is called exit pupil. Exit pupil is calculated (in millimeters) by dividing the diameter of the objective lens by the power of the scope. Your eye pupil can vary from 4mm to 7mm in low light, and the quality rifle scopes will deliver an exit pupil of 3 to 3.5mm on the high setting.
Quality rifle scopes range in price from $350.00 to $2800.00. The Top of the Line scopes are Leupold, NightForce, Schmidt & Bender, Swarovski, U.S. Optics, Zeiss, and Burris to name a few. The Success of your long range shooting endeavors will be dependant on the Consistency and Repeatability of Windage and Elevation Clicks, and the Quality of Glass of the Scope you have mounted on top of your Rifle.