When choosing an infrared rifle scope, there are many factors that must be examined. While the purpose of a rifle scope is to hit a target, the first and foremost factor is to select an infrared rifle scope that has a shooter-friendly sighting system. While the typical sighting aperture in an infrared rifle scope is a tactical type optic, hunters may wish to choose a cross-hair-type aperture. Magnification in an infrared rifle scope is typically best in the three to five power range; however, three to nine power units are typically preferred by hunters.
Prior to purchasing an infrared rifle scope for any rifle, it is wise to check the local laws and ordinances governing such devices in any given area. While some areas will allow the use of an infrared rifle scope, most areas around the world will not. Save for some types of varmint hunting, sunset is typically the end of shooting hours in nearly all areas of the world. Law enforcement and military personnel, however, frequently use an infrared rifle scope to meet the requirements of certain objectives.
While it is frequently difficult to gauge the size and distance of a target due to not being able to see surrounding objects after dark, the design of the sighting optic is a critical component of a night-vision scope. The color of the optic is just as important as the style of the targeting design. Many shooters prefer a green back lighting with a red optical targeting sight in a night-vision scope. The green is softer on the eye while the red is easily recognized by the human eye. Some shooters who have used a red back lighting with a green sighting optic have reported eye fatigue when forced to peer through the scope for long periods.
The magnification power of the scope is also a critical factor in choosing the best scope for a rifle. If using the scope for long-distance shooting, a higher magnification is generally preferred by most shooters. In low-light situations, however, a scope with less magnification will often provide a clearer sight window. Typically, a compromise in magnification will prove to give the shooter the most usable and comfortable infrared rifle scope in any given situation. The ability to adjust the intensity of the infrared rifle scope is often a determining factor for many shooters who wish to not have to peer into an intensely bright scope at all times.