SCOPES
Scopes are optical instruments composed of stationary and moving parts enclosed in a housing. Scopes serve to magnify and define a target in a manner which presents the shooter with a sight picture that allows the full potential of the firearm and cartridge to be accurately realized.
With optics such as rifle scopes, it is advisable to invest in the finest quality you feel is justified, yet affordable. The reason for this is that you will eventually outgrow a cheap scope due to dissatisfaction with its performance. The initial investment will be wasted when you acquire a scope that will stay with you for life.
Scopes function by incorporating an optical system which is intended to maximize the amount of pure light delivered to the shooter's eye. Light rays from the target image enter the objective lens at the front of the scope and are magnified.
The resulting enlarged and upside-down image is magnified and corrected to the right-side-up position by the erector lens system typically found in the middle portion of the scope's main tube. Lastly, the target image is further magnified by the ocular lens at the rear of the scope. This lens projects the target image, as well as the central aiming point, known as the reticle (reticule) or "crosshairs", to the shooter's eye.
The single most important indication of a scope's ability to manage light is its ability to provide contrast. Contrast is enhanced by resolution, which is the characteristic of producing a crisp, finely detailed image.
Contrast is also enhanced by light transmission, a parameter that is affected by the number of glass or mirrored surfaces, the absorption of light in the glass materials, and the quality of the anti-reflective and mirrored coatings. Contrast is degraded by glare, which is the stray light that reflects off internal parts of a scope and enters the field-of-view. Glare also diminishes detail and color quality of the image.
The exit pupil is the circle of light a shooter sees when the scope is held at arms length. It is a measure of the quantity of light that reaches the shooters eye, and is not influenced by the diameter of a scope's main tube.
In typical low-light conditions in the field, a shooter's eye dilates to a pupil width of about 5 mm. If the exit pupil of the scope is smaller than the shooter's pupil, too little light will reach the shooter's eye and the scope will impose limitations on the shooter's ability to see.
Parallax is the perceived movement by the target with respect to the reticle that a shooter experiences when the eye is shifted slightly from side to side. Parallax is normally eliminated by manual adjustment of the objective lens or by manual adjustment of a parallax knob, depending on how the scope is equipped.
Eye relief is the distance between the eyepiece at the rear of the scope and the shooter's eye which is required to project a target image that is in focus. Short eye relief is dangerous because the shooter can be struck in the eyebrow by the back of the scope when the firearm recoils after a shot. The shooter is much less likely to be injured while shooting when there exists ample eye relief.
Other features typically found on scopes include windage and elevation adjustments, which allow the shooter to sight-in the firearm or make field corrections based on actual conditions.
A power selector ring is provided to adjust magnification on variable power scopes.
Scopes may be provided with a sun shield as an option to reduce glare and may or may not possess lens covers to keep dust or moisture from obscuring the surface of each lens.
Scopes come in a wide variety of magnifications suited to particular tasks. Variable magnification scopes have an advantage over fixed power scopes in that magnification may be adjusted to address a variety of shooting situations.
Fixed-power scopes are adapted to well defined needs where parameters are known. Fixed power scopes are generally viewed as being able to better withstand severe use, due to the reduced number of moving parts. The perceived edge is not great, however, considering the quality of variable-power scopes now available, and their useful versatility.
Field of view is the picture presented by a scope to the shooter at specific magnifications. Its diameter is typically measured in feet. For example, a 20x power scope, with a field of view of 5.5 feet, will present a target shooter with an extremely detailed picture of the target area at 100 yards, but will show little to the sides of the target.
This presents no problem when the target area is fixed, but greatly inhibits target acquisition when the target location is unknown or mobile. For this reason, a variable power scope of approximately 3-9x magnification is typically regarded to be ideal for general hunting due to the range of field of view provided (32 feet, low power; 14 feet, high power at 100 yards).
The reticle is the "cross hair" feature of the scope. It represents the point of aim. The duplex design, which consists of a cross of heavy posts transitioning to thin lines at the cross's midpoint, is very popular. The shooter's dot is a ubiquitous reticle, and consists of a dot in the middle of thin cross hairs. The 3/4-mil dot, created by the U.S. Marine Corps for snipers, is now the standard range estimating reticle for all branches of the military service. Dots are spaced in one mil (milliradian) increments on the cross hair. The distance to the object being targeted can then be determined based on object size and the mil formula. Conventional crosshairs, consisting of thin intersecting lines, often serve as a reticle.
Each Leupold scope requires mounting rings to secure the scope to the rifle or handgun. Scopes do not come with this necessary mounting hardware due to the myriad of potential applications, each of which is unique. Leupold manufactures literally hundreds of different mounting rings , each designed for fitting a particular scope to a particular make and model of rifle or handgun. If you have access to a Leupold catalogue, or have perused the Leupold website at www.leupold.com , you may feel comfortable selecting a specific Leupold mounting ring model number that meets your needs.
If you are unsure of the Leupold mounting ring model number, again please e-mail the Armory, this time specifying the Leupold model scope and the make and model of the firearm to which you wish to mount the scope. You will receive a follow up price quote on the appropriate mounting rings.
The Armory is now a direct dealer for Aimpoint red dot rifle and handgun scopes. The Comp ML2 and Comp ML2-2x models have been adopted for use by the U.S. military. They are finding application in Iraq and Afghanistan, where their ability to assist rapid acquisition of targets is protecting the lives of American servicemen and women.
All the Comp models are well suited to installation on the AR-15, the civilian version of the military M-16. The forward mounting position is preferred by many, using the spacer, the quick release Picatinny mount and the AR-15 forward mount. Handle installation, also a favored set up, can be easily accomplished by using the carry handle mount and the quick release Picatinny mount. Either scope position provides for "cowitnessing": that is, use of the iron sights in the event the scope experiences catastrophic damage.