September 23, 2010
Battery-powered electronic sights are available in a variety of types for different types of shooting. Here is a look at three of the newest.
Before 1975, nobody in America knew what an electronic dot sight was. That year a Swedish company introduced something called the Aimpoint to the U.S. market. The Aimpoint was a flattish little box about four inches long with small lens apertures at both ends. It was billed as a "battery-powered, parallax-free non-magnifying electronic optical sight" and had originally been designed for close-range rifle hunting in the darkly forested moose country of Scandinavia.
Its importers believed it would have the same type of application for eastern woodland deer hunters in this country and expected it to become as popular as it had in Europe. But American hunters yawned and shrugged.
Then in 1979 U.S. Army Reserve Sgt. Joe Pascarelli put an Aimpoint on his 1911 Government Model .45 ACP pistol and won the National Pistol Championship at Camp Perry. A picture of him holding the gun made the cover of the NRA's American Rifleman. And everything changed. Electric "dot sights" were in--from bullseye to speed shooting, from long range to close range, from the Bianchi Cup to the Steel Challenge to Camp Perry to the USPSA Nationals to the IPSC World Championship. It was no joke that when the newly crowned 1992 USPSA National Champion, Todd Jarrett, stepped to the microphone to accept his title his first words were to thank Duracell batteries. Competition shooting was changed forever.
And in much the same way that high-tech vehicle performance features that win races soon find their way into your family car, so did ordinary shooters and hunters quickly catch on to the benefits of electronic sights and begin to use them in large numbers for the applications their inventors had envisioned.
Today, a large mix of "dot sights" sit on firearms of all types. As optical and miniature-electronics technology advanced over the last 20 years, the original squarish shape and mediocre lens quality of the original Aimpoint (necessitated by the then-bulky electronics) has given way to larger optical-tube configurations (up to 50mm lens diameter in some makes) and to "single lens" designs employing holographic imagery and/or laser-generated reticle projections--some of which are stunningly compact and function almost like the "heads up" displays of modern combat aircraft. Virtually every optical-sight company has at least one electronic model in its catalog, and new styles and designs are introduced yearly with an increasing array of different shapes, sizes, and even colors available in the reticles/dots.
Here's a brief look at three of the newest electronic sights from three leading optics manufacturers. Each represents a very different technical design approach.
Burris SpeedDot 135
Well-known scopemaker Burris (Dept. ST, 311 E. 8th St., Greeley, CO 80631; www.burrisoptics.com) entered the electronic-sight marketplace a little over two years ago with the introduction of its initial SpeedDot 135. Of the three sights reviewed in this article, the SpeedDot 135 is the most "conventional" in that it features the closed-tube, multiple-lens setup that succeeded the original Aimpoint box as a standard format for dot sights generally. Like most such nonmagnifying optical sights, it looks much like a stubby 1X scope with lenses at both ends and external windage and elevation adjustment knobs.
Tube diameter is 1.36 inches, with 35mm objective and ocular lenses. The tube is nitrogen filled and sealed to be waterproof and fogproof. Optics are fully coated for nonreflective sight picture. Overall finish for the SpeedDot 135 and accessories is matte black. Each SpeedDot 135 comes fully equipped with everything needed to mount and go--including a pair of Weaver-type 35mm mounting rings that will fit standard Weaver-type cross-cut bases, a screw-on tube extension sunscreen to deflect low-angled external light, lens covers, and an industry-standard No. 2032 camera battery with 200-hour-plus use life (replacement batteries are available anywhere batteries are sold). The sight weighs just five ounces; the rings add 2.7 ounces more.
The Burris SpeedDot comes accessorized with Weaver-type mounting rings and a screw-on sunshade extension; it offers 11 brightness settings and has a removable battery cap and easy-to-grasp elevation/windage adjustment knobs; and it is durable. The author's SpeedDot has held up through 1500 full-power .41 Magnum rounds with no problems or shift in position of its 50-yard zero.
The battery is placed inside the brightness-setting ring on top of the scope body. Battery replacement is simple, via a coin slot in the cap, but you have to remember that merely turning the coin will rotate the whole adjustment ring and not unscrew the cap. To open the battery compartment, you have to grip the brightness setting ring and hold it in place while using the coin to unscrew the cap from the ring. The brightness ring itself has 11 settings plus "0" (off). You can use the different settings to accommodate different ambient light conditions and also to compensate for a weakening battery. (To conserve battery life, the adjustment ring should always be set to "0" when not in use.)
The SpeedDot 135 is offered with either a three MOA (minute of angle) dot or an 11 MOA dot. These angular measurements translate into approximately three inches and 11 inches target-coverage (subtension) at 100 yards. The three-minute dot is preferred by precision shooters and hunters seeking exact shot placement. (It essentially marks the X-ring of a standard NRA bullseye target at 25 yards.) The 11-minute dot is the choice of action-pistol competitors and speed shooters because of its high visibility and quick acquisition for relatively large targets at close distances.
Burris presents the SpeedDot 135 as "built to withstand magnum recoil" and emphasizes its usability for shotgun aerial-target shooting and centerfire rifle/handgun hunting as well as pistol competition. To acquire some practical assessment of these claims, I provided the 11-MOA SpeedDot 135 sample Burris sent to Shooting Times to an avid local trap-league competitor who put it on his 12-gauge Remington 11-87 and has used it continuously for practice and matches throughout the 2001 summer league sessions. His round count is now over 3000 rounds fired with no failures, malfunctions, or shifts of zero.
I also mounted the Burris three-MOA sample SpeedDot 135 on a new 71/2-inch S&W Model 657 .41 Magnum revolver. I have been using it exclusively for four months while developing an extensive .41 Magnum handloading project. I've put m
ore than 1500 rounds under it with no problems and no shift in the precision of its 50-yard zero.
So far, I'd rate the SpeedDot 135 as being as good as a dot sight gets.
The new Bushnell HOLOsight II is notably more compact than the bulky first-generation version; it configures well to a frame-top mount on the author's S&W Model 610 10mm hunting rig; and the precision of its 1/2-minute interval windage and elevation adjustments impressed Dick.
Bushnell HOLOsight II
The initial HOLOsight model from Bushnell (Dept. ST, 9200 Cody, Overland Park, KS 66214; www.bushnell.com) was the first major technological advance in electronic sight design to come after the original concept of a parallax-free internal-projected reticle as embodied in the Aimpoint and all subsequent tube-style electronic sights. The difference between the HOLOsight and a conventional dot sight such as the SpeedDot 135 is subtle but significant. Both are nonmagnifying and parallax-free. Both offer heads-up, both-eyes-open viewing of the target, with aiming points displayed as electronically generated images. However, the dot reticle of a tube design is projected to function as a conventional optical reticle within the sight body (i.e., between the ocular and objective lenses, much like a conventional scope reticle).
The HOLOsight, on the other hand, is a "single-pane" sight with no lenses per se. Instead, it uses laser light to illuminate a holographic reticle image that is embedded in a "display window" and projects the appearance of the reticle as being suspended--floating--50 yards in front of your gun. Field of view is unlimited, as is eye relief. (Technically, the eye-relief is from 1/2 inch to 10 feet, but if you're holding your gun less than a half-inch from your eye you need counseling. And if your arms are more than 10 feet long, you're on the wrong planet.) With a HOLOsight, if you can see the reticle and it's against the target, you're on (assuming it's zeroed, of course). Head and gun do not have to be perfectly aligned.
The laser diode in a HOLOsight is a federal-definition Class II Laser Product, operating at 0.08 milliwatts and 650 nanometer wavelength--much less power than a Class III laser-sighting device but still not something to look directly into. (The illuminating beam is completely blocked by the sight housing and is visible only if the housing is broken.) The visible holographic reticle image is not the laser but is merely illuminated by the laser so you can stare at it all day long. And because the laser holograph does not actually illuminate the target but merely creates the illusion of a lighted aiming point against the target, the HOLOsight is legal for hunting anywhere a conventional illuminated-reticle scope is legal (in some states actual projected-beam laser aiming devices are not).
HOLOsight reticles are available in two styles: a one MOA dot (for true precision aiming) and the Standard (original) "dot-in-a-circle" design. As just a rough guide, the circle that surrounds the dot subtends the approximate diameter of a 12-gauge trap load shot cloud at 30 yards. When you're shooting clay targets, if the bird is inside the circle when you press the trigger, it's powder. The setup also has obvious applications for moving target lead and long-range trajectory compensation.
The differences between the original HOLOsight and the new HOLOsight II are primarily size plus several added functional features. The first-generation HOLOsight was actually quite bulky--almost as big as a full-size tube sight, in spite of being a lens-free single-pane sight. The HOLOsight II is much smaller. Significant features include 20 brightness settings with improvements in lower setting luminosity for better hunting use in very low light (so as not to overpower and "bright out" the view of the target), a tool-less battery compartment for change of batteries without the previously required hex-wrench, an automatic battery-check signal that warns the user of the approaching need to replace batteries, and an automatic shutoff after eight hours to help preserve battery life. (The power drain of the HOLOsight's laser system is considerable as compared to a conventional dot sight and is good for only about 40 hours. But the two Type N alkaline 1.5V batteries it uses are available anywhere.)
I have been very impressed with the Bushnell HOLOsight since I saw some of the earliest prototypes tested at PASA Park by IPSC/USPSA champion Jerry Barnhart. The precision of its 1/2-minute interval windage and elevation adjustments was particularly impressive. The only negative has been the largish size. The HOLOsight II goes a long way to fix that, and it configures well to a frame-top mount on the S&W Model 610 10mm hunting revolver I've been shooting it on. I'm really looking forward to HOLOsight III.
Tasco Optima 2000
Tasco's Optima 2000 (Dept. ST, 2889 Commerce Parkway, Miramar, FL 33025; www.tascosales.com) represents a "third generation" in electronic sight configuration and is in several ways a hybrid between conventional dot-sight tube designs and single-pane image projection. It utilizes a single-pane viewing window with laser-illuminated (Class II) LED reticle-image generation. The reticle, however, is a simple dot and floats on the same plane as the gun's iron sights (rather than being "projected" forward to the target plane as with the HOLOsight).
The most notable aspect of the Optima 2000 is its extraordinarily compact size; it's not much larger than many adjustable target-grade rear iron-sight mechanisms. The sight body fits into a mounting base (a Weaver-type crosscut clamp is standard), and bases are available that fit into the dovetail rear-sight slots of specific auto pistol models. The LED insert consists of a waterproof encapsulated microelectronic unit with gold-plated battery contacts extending out either side.
The battery fits into the bottom of the sight body and is enclosed when the sight is attached to a mount base. When inserted, the positive side of the battery should be visible and the side of the battery needs to be pressed against the contacts before being seated in its hole (if the negative contact is not properly situated in its recess or is bent out of position, it may touch the positive side of the battery and the LED will not illuminate). The Optima 2000 uses a three-volt lithium type CR2032 camera battery (the same as the Burris SpeedDot).
Tasco's Optima 2000 sight comes with standard base mount, snap-on cover, adjustment tools, and battery; is fully adjustable for windage and elevation and utilizes a small hex wrench with an index Microdial for precise measurements; and its clean, cl
ear dot definition allows a precision sight picture and encourages excellent groups.
The LED insert comes in two sizes: 3.5 MOA for precision shooting (and longer battery life) and seven MOA for action-pistol shooting and shotgun aerial-target applications. (LED change is available by factory service; the two reticles are sold as different models.) There are no manual brightness controls. The LED insert senses ambient light and controls the output of the laser illumination to give optimum visibility of the dot against the target. For unusually bright conditions, and in some types of competition shooting, a brighter dot may be preferable. In that case two CR2016 batteries may be used to provide a six-volt power source instead of the standard three volts a single CR2032 provides. Dual-battery setup requires both positive sides be stacked "upwards" with the sight's positive contact point touching only the outermost battery. Battery life with the six-volt setup is only about half of the standard three-volt system.
The Optima 2000 has no on/off switch. Instead, the sight comes with a snap-on plastic cover, which, when installed, cuts off all external light and puts the LED into "sleep" mode (thus the sight does not function in a totally dark environment). The absence of brightness and manual on/off controls are both a function of the Optima 2000's extremely small size and an intentional effort to make the sight as "automatic" as possible to use. Small as it is, the Optima 2000 is nonetheless fully adjustable for windage and elevation using a tiny hex wrench and a small plastic Microdial that fits over the wrench to provide an index for the amount of adjustment. One adjustment interval on the dial equals one inch of reticle displacement at 20 yards.
The test Optima 2000 came with the 3.5-minute reticle, and I mounted it on a Colt Model 1911 in 9x23mm Winchester using an Aimtech grip-replacement base to check how precisely it would permit aiming. The dot display was very clear and crisp-edged, with no "flare" or "halo," which made it very easy to maintain a repeatable sight picture. With that gun and iron sights I get roughly 2.25 inch average groups at 25 yards, but with the Optima 2000 the average for five full-magazine strings at that distance was about 1.88 inches. The Optima 2000 is manufactured in England and imported by Tasco. It is also available under other brand names as the FirePoint sight and the Dr. Optik sight with somewhat different feature and accessory sets. It represents the current state-of-the-art in electronic sight miniaturization.