Reflex Sights
Reflex sights, you could say, date to 1900, when Irish optics engineer Sir Howard Grubb patented a “Collimating-telescope Gun-sight” without “imperfections inherent in the old form of telescope-sights.” His design used a reflecting surface to project an adjustable reticle into the shooter’s vision. During WWI reflex sights enabled German Fokker pilots to aim their dual Spandau machine guns.
Sir Grubb’s idea and Teutonic engineering took most of a century to refine. In 1975 Swedish inventor Gunnar Sandberg developed what he called a “single-point sight.” You didn’t look through this sight, rather you looked into the tube with one eye while your other registered a dot superimposed on the target.
Sandberg founded a company, Aimpoint, which went on to define this type of sight. You could see the illuminated dot from almost any place behind it. The front lens of an Aimpoint sight is compound glass that corrects for parallax. It brings the dot to your eye in a line parallel with the sight’s optical axis so you hit where you see the dot even when your eye is off-axis. Like holographic sights, reflex sights have limitless ER, but they’re not forgiving of astigmatism.
Now generations of Aimpoints later, these sights are smaller and lighter but sturdy enough for military use. Advanced circuitry has reduced power demand; batteries now last up to 50,000 hours at mid-range brightness settings! Positive windage and elevation clicks move impact 13mm at 100 meters. A 3.5-oz. Micro S-1 was designed for mounting at mid-barrel on shotguns where its optical axis is snug to the rib. It has a 6-minute dot with 12 intensity settings. At least one in 10 glass-equipped moose rifles in Sweden wear an Aimpoint. I’ve used them on two moose, both in dark forest.
The first ghosted by at 70 yards, in very low light. I waited to shoot but followed the bull with the sight. He paused at 90 yards, just his shoulder visible in the gloom, where the Aimpoint’s dot found it. My .30-06 bullet struck spot on. Years later another bull was milling, with two other moose, at thicket’s edge. Brush stopped my approach at 80 steps. I saw only blinks of hair through a small alley and couldn’t tell which beast was which. Then antler base and neck stalled in the opening. Again the Aimpoint’s bright dot came instantly to bear. The moose fell to my Norma bullet from a double rifle in .375 Flanged.
Both the closed (tube) and open reflex sights function the same way. The reticle is a reflected LED image focused on the glass screen. The dot in a closed reflex sight is as bright a reticle as you’ll get in any sight. A closed sight also protects the light path from weather and from obstruction. A leaf blown atop an open reflex sight kills the reticle, at least temporarily. The advantage of the open design is lightweight. Leupold’s DeltaPoint Pro, with its 33mm lens, weighs 2 oz., as does Trijicon’s RMR and Sightmark’s Core Shot A-Spec. Bushnell’s Advance Micro Reflex comes in at 2.2 oz., the Burris Fastfire at 1.5 oz. Triple the heft for a closed reflex sight. Holosun lists its $227 HS503G at 4.9 oz. It and the 5-oz. Burris SpeedDot are lightweights for the closed type.
