Those of us over-40 types can use some help when shooting iron sights. As one gets older, your eyes lose the ability to rapidly adjust to different points of focus. In practice, when shooting a rifle, this means the target image may be sharp but the sights are blurry, or vice-versa. Or you may be able to see the target and front sight reasonably well, but the rear sight is a complete blurr. (That is this Editor’s problem when shooting a rifle, such as a Swedish Mauser, with a notched blade rear sight.) Even if you are using a rear peep sight, you may see a blurry rear circle (or two circles if you have astigmatism). Placing a diopter on your shooting glasses can help many people see open sights better, when shooting both handguns and rifles.
Merit Corp. in Schenectady, NY, offers an adjustable metal diopter that attaches to shooting glasses with a rubber cup. Though primarily intended for pistol shooters, the Merit diopter can also be helpful when shooting rifles with open sights, such as military bolt actions. Priced at $65.00, the Merit device features a shutter-style adjustable aperture iris.
Merit explains: “The human eye, whether or not prescription glasses are required, cannot focus on both sights and the target at the same time. The eye will constantly shift focus from the sights to the target trying to ensure proper alignment. Unfortunately, as we age, the eye loses the flexibility which allows it to do this; thus, sights and target begin to grow fuzzy. There is a simple way to combat this by increasing your eyes’ depth of field (range of focus). If you look through an aperture or pinhole of the correct size, you will be able to see both sights clearly, and the target will be clearly defined as well.”
In addition to diopters for eyeglasses, Merit produces a variety of adjustable iris sight products for rifles, including the Variable Iris Aperature for AR15s. Visit MeritCorporation.com or call (518) 346-1420.
Cheaper Diopter from Lyman
If you can’t afford a Merit adjustable diopter, Lyman offers a similar all-plastic device for under $20.00. The Lyman Hawkeye Shooting Aid mounts directly to your eyeglass lens with a rubber suction cup. The diopter section is made of plastic, and aperture diameter is non-adjustable.
Though it is simple and inexpensive, the Lyman Hawkeye works for many shooters, if positioned properly. (Don’t think this is anything close to the Merit Diopter in quality though!) Currently, Cabelas.com has the Lyman Hawkeye on sale for just $12.88, item # IK-229094. MidwayUSA sells the Lyman Hawkeye for $18.99, item # 936878. One MidwayUSA customer reports:
“This thing really works! I have it on my shooting glasses, and it has made a significant improvement in my ability to keep the front sight and target in focus at the same time. If you are older and find that you are having a hard time keeping the target in focus over ‘iron sights’, then this may be the answer to your problem. Mine works equally well for both pistol and rifle, although I do have to change the device’s position on my shooting glasses when changing weapon types.”
Forum member Roy Bertalotto did a real nice off-set scope installation on a bolt gun to help a sight-challenged shooter. Roy explains: “A friend of mine shoots left-handed and has lost the sight in his left eye. I built him a scope mount so he can still shoot left-handed, but now use his right eye.” Roy’s fabrication work is impressive and we praise his efforts to help a fellow shooter stay in the game.
Roy bolted a plate to the existing scope rail on the top centerline of the Rem 700 action. This plate extends a few inches to the right. On the outboard end of the plate, Roy fitted a second scope rail, aligned with the bore. Weaver-based rings are then clamped to the outboard (right side) auxiliary rail.
Be Careful of Canting Issues with Offset Scope Installations
We’re pleased to see that Roy developed a solution for a shooter with an optical disability, but we want to stress that this is a specialized installation that can create some problems with point of impact shift if the gun is not maintained perfectly level. With the amount of horizontal offset (between the scope’s optical axis and the bore axis) built into this rig, if the rifle is canted, point of impact can shift rather dramatically. For a southpaw who is willing to adapt his/her shooting style, it may be better, in the long run, to learn to shoot right-handed if his/her right eye is the only good eye. Likewise, if a right-handed shooter can only see well through his left eye, he may benefit from learning how to hold the stock and work the trigger with his left hand. The shooter could still work the bolt with his non-trigger hand. Changing from right-hand to left-hand shooting (or vice-versa) may require a stock swap if the stock is not ambidextrous.
Burris Signature Rings in Stock Again
Because they allow you to mount a scope without markings, to “pre-load” elevation, and to correct for windage mis-alignment, Burris Signature Rings are extremely popular. So popular in fact that Signature Posi-Align Rings, particularly the “Zee” models for Weaver rails, have been back-ordered for months. Well, Signature Ring fans can now celebrate. Burris has recently shipped large supplies of Signature Rings, including the hard-to-find 30mm High Zees, to vendors across the country. If you’ve been waiting on these unique, affordable ring sets, get your orders in now.
A quick search of webstores shows that various models of Burris Signature Rings are available from all of the following vendors. NOTE: You may have to check with more than one vendor to get the exact size, height, and model you prefer. Inventories are subject to change on a daily basis. For example, Midsouth expects to get some more 30mm Signature Zee High rings in a couple days from now.
Bruno Shooters’ Supply: 1″ and 30mm Signature and Universal, 1″ Rimfire Signature Zee (Call for availability of sizes).
Eabco.com: Signature Zee 1″ and 30mm, Medium. (High — call for availability).
Midsouth Shooters Supply: Wide selection — 1″ and 30mm Signature Zee, Universal, Dual Dovetail, and 1″ Rimfire Signature Zee. (NOTE: 30mm Signature Zee High expected 6/19/2012.)
Sinclair International: 1″ and 30mm Signature Zee, Universal, and Dual Dovetail. (30mm High and Xtra-High Zees out of stock temporarily).
Last fall we announced that Leatherwood/Hi-Lux Optics would be adding an 8X Unertl-type scope to its William Malcolm Series of externally-adjusting riflescopes. Well, the wait is finally over folks. The Hi-Lux Malcolm 8X USMC-Sniper Scope is now in stock and on sale at Creedmoor Sports for $549.00. This should prove quite popular with Vintage Sniper Rifle Match competitors. The new USMC repro scope duplicates the original windage and elevation controls on the 50s/60s-era USMC scope — but the new Hi-Lux offers modern multi-coated lenses.
Scopes of this design, with micrometer click external adjustment, were once favored by long range shooters. The Marine Corps utilized this style of externally-adjusting scope on sniper rifles during WWII, Korea, and the early stages of the Vietnam conflict. Today, a mint-condition, original USMC-marked scope can sell for as much as $5,000. And with the current interest in vintage sniper rifles, just a working standard model Unertl scope in good condition can still bring $2,000 or more.
With its $549.00 price at Creedmoor Sports, the Hi-Lux USMC-Sniper repro scope is far more affordable than a serviceable original. Like all Leatherwood/Hi-Lux Optics, the Wm. Malcolm USMC-Sniper model comes backed with a limited lifetime warranty. Each 8X USMC-Sniper repro scopes will be serial numbered — as were the original USMC models. Leatherwood/Hi-Lux also sells a variety of long-tube, external-adjusting scopes that are quite popular with BPCR shooters and vintage rifle fans.
Scientists at the Oak Ridge National Laboratory (ORNL) have developed a system that uses lasers and fiber optics to measure very small changes (deflections) in a rifle barrel. These deflections are recorded with laser sensors, and then algorithms are used to compute the resultant changes in bullet trajectory. Using computer-calculated trajectories, the digital sighting system’s “virtual” reticle automatically adjusts to compensate for barrel deflection, as well as changing environmental conditions. The microprocessor-controlled digital reticle can adjust to 1/1000th of a Minute of Angle (MOA). That makes it far more precise than any conventional riflescope reticle.
ORNL Barrel Sensor with Compensating Reticle
Shown below is a laboratory prototype of Oak Ridge National Laboratory’s Reticle Compensating Rifle Barrel Reference Sensor. This system precisely measures the deflection of the barrel relative to the sight and then electronically makes the necessary corrections. The system was developed by a team led by Oak Ridge National Laboratory’s Slobodan Rajic, shown in the photo.
The Reticle Compensating Rifle Barrel Reference Sensor takes the guesswork out of shooting by shifting the burden of knowing the relative position between the barrel and the weapon sight axes from the shooter to an electronic sensor. The system precisely measures the deflection of the barrel relative to the sight and then electronically realigns the moving reticle, or crosshairs, with the true position of the barrel, or bore axis.
“When a weapon is sighted in, the aim point and bullet point of impact coincide,” Rajic said. “However, in the field, anything that comes into contact with the barrel can cause perturbation of the barrel and induce errors.”
With modern high-caliber rifles boasting ranges of up to two miles, even very small barrel disruptions can cause a shooter to miss by a wide margin. That makes this technology indispensable from a marksman’s perspective, Rajic said.
From a technological standpoint, the approach is straightforward. ORNL starts with fluted barrels (the flutes play a key role). With the ORNL technology, glass optical fibers are placed into the flutes. The sensor system contains a laser diode that sends a signal beam into the optical fibers parallel to the bore axis of the barrel.
“The optical fibers are designed to split the laser beam twice, sending one beam along the top of the rifle barrel and another light beam along the side of the barrel,” Rajic said. “Thus, we can measure both the vertical and horizontal barrel deflection.”
Through a combination of algorithms, optics and additional sensor inputs, the system can take into account distance and other factors affecting the bullet trajectory. Ultimately, the whole optical/laser/digital system provides the shooter with crosshairs that automatically adjust for conditions in real time.
A Compensating Reticle with 1/1000 MOA Precision
Skeptics of electronic sighting systems have complained that the resolution of a digital rifle-sight is too crude to allow precise aiming. There simply aren’t enough pixels on a viewscreen to allow ultra-precise aiming at long-range targets, shooters have said. In fairness, the existing commercially-available digital rifle sighting systems HAVE been crude — with a lo-rez screens like you might find in a portable GPS.
Well you can forget all that. ORCL has achieved a break-through in digital sighting. The bar has been raised — by an order of magnitude. The resolution of ORNL’s digital, sensor-informed Compensating Reticle is 125 times better than that of traditional target reticles, which can normally be adjusted by one-eighth Minute of Angle (MOA) (at best). Now get this — the ORNL sensor can sense angular displacement and shift the reticle by 1/1,000th of a minute of angle. While this system is expensive, and designed (at this point) for the military, this technology could eventually benefit sport shooters. A decade from now, we would not be surprised if long-range civilian shooters commonly use electronically-enhanced optics, with digital reticles that automatically compensate for bullet drop (and maybe even windage).
ORNL scientists are also working on technology that could yield much more precise and accurate plots of bullet trajectories. We will no longer have to rely on “guesstimated” data inputs, and certain assumptions about bullet drag factors. Rajic and colleagues are developing a laser-based, bullet tracking system that would record plot the bullet’s actual flight path while the bullet is in the air. In other words, this tracking system would be able to plot the bullet’s true trajectory from muzzle to target. That is much differerent than current ballistic “solvers” which merely draw a predicted arc based on muzzle velocity, wind and temp inputs, and a reference BC value.
Oak Ridge National Laboratory is a multi-program science and technology laboratory managed for the U.S. Department of Energy by UT-Battelle, LLC. Over 3000 scientists and engineers at ORNL conduct basic and applied research and development to create scientific knowledge and new technology in key areas of science, energy, the environment, and national security.
The June Digital Edition of GUNS Magazine is now available for free online. Just click this link to view the June Edition. NOTE: When the log-in screen appears, simply click the “CONTINUE” button. You do NOT have to fill in your name or email address. You can also read previous monthly editions by clicking on the Archive Tab. The last three (3) years of GUNS Magazine can be accessed for FREE online.
Articles by Jake Gottfredson in June Edition
The June Edition of GUNS Magazine contains two interesting articles by our friend (and AccurateShooter contributing writer) Jacob (“Jake”) Gottfredson. In the first article, Some Basic Riflescope Theory, Gottfredson identifies key principles of optics and shows how they apply to riflescope design and construction. He explains the term “Modulation Transfer Function” (MTF), and how this can be used to quantify both contrast and resolution. The author also explores the topics of color correction, chromatic aberration, and color fringing. Jake notes how color correction and focus precision are directly related. Jake also explains the difference between “clarity” and “resolution”. You can have a scope with good clarity but poor resolution or vice-versa. If a scope shows cloudiness it lacks clarity. If the scope can’t show a test grid in sharp focus, it lacks resolution. There are many other important insights Jake provides in this well-written article. We recommend you read the article and perhaps event print it out for future reference. If you are shopping for an expensive scope, Jake provides specific criteria by which you can judge a scope’s quality and repeatability.
600-Yard Playing Card Shoot — Tiny Target, Far Away
The second offering by Gottfredson in the June issue of GUNS Magazine, is an entertaining report about a 600-yard fun shoot using playing cards. Regular-sized 2.5″ x 3.5″ playing cards with a 3/4″ red dot are placed in the center of an 8.5″ x 11″ target sheet. To help aiming, the target sheets have a black ring about 5″ in diameter. After a sighter session, shooters are allowed 10 shots in 7 minutes from 600 yards. That’s a pretty tough challenge, but with a very accurate rifle, multiple card hits are possible. Jake reports that, at his “card shoot”, the two top competitors, Gary Chaney and Andrew Smith, each hit the card six (6) times, with Gary breaking the tie by hitting the 3/4″ red dot. If this sounds like fun, read the full story, and perhaps you can set up a similar match at your shooting club. Gottfredson even includes “10 Tips for Success” such as: “7. Shoot fast, trying to get all rounds downrange in the same wind. Stop when it changes and wait for it to return or hold off if it does not….”
In addition to two Gottfredson articles, the June Edition of GUNS Magazine has a helpful feature on the .243 Winchester by John Barsness. This provides a short history of the cartridge and Barsness discusses 6mm bullet options for hunters using the .243 to harvest game.
Imagine a “smart scope” that can range your target AND calculate windage correction. Such technology may appear in riflescopes fairly soon. The Israeli Government’s Soreq Nuclear Research Center has received a U.S. patent for a new laser-based technology that can gauge wind vectors as well as target distance, using a laser rangefinder coupled to a rifle-scope. The Israeli system is called LIDAR, an acronym for Laser Identification Detection And Ranging. This new technology could, potentially, be a major boon for long-range shooters, both military and civilian. Ironically LIDAR was first developed for environmental monitoring (not for use with weapons). A LIDAR system was used for 3-D mapping and modeling of wind-driven plumes from the Israel Electric Company’s Rabin power plant.
Credit The Firearm Blog for breaking this story on the new Israeli LIDAR technology for sniper scopes. Below you’ll find the LIDAR Patent Application Abstract, which has a good summary of how LIDAR reads the wind.
The new Israeli LIDAR unit gauges wind speed by detecting fluctations in laser signals sent out from the integrated scope/LRF, reflected back from the target, and then received by photodiodes in the scope/LRF. Other scopes have used built-in LRFs to measure distance-to-target, but Israel’s patented LIDAR goes one step further, using the laser to gauge BOTH target distance AND wind vectors (i.e. velocity + direction). This information is entered automatically into software. The software then calculates a ballistic solution compensating for distance, wind angle, and wind velocity. If it really works, LIDAR represents a remarkable technological achievement. The Israelis claim LIDAR works for targets at distances of 500m or greater. Why won’t it work at closer ranges? Presumably the wind-induced laser fluctuations are too small to register at closer distances.
Current Integrated LaserScopes for Hunters While the Israeli LIDAR system may seem like science fiction, it’s not that far removed from the lastest commercial optics. Engineers on both sides of the Atlantic have already integrated laser rangefinders (LRFs) into rifle-mounted “consumer” optics. Just this year, Burris introduced an affordable “consumer” scope, the Eliminator, that ranges the distance to target and then displays the ballistically correct aiming point on the vertical crosshair. The amount of hold-over is automatically calculated with reference to ballistics formulas. At right is a view through the Burris Eliminator; the illuminated dot shows the calculated aiming point.
While such technology can help a shooter compensate for bullet drop, windage compensation is another matter. A shooter must still gauge crosswind angle and velocity, and then hold left or right accordingly. If the LIDAR system can perform this task reliably, that is a major advancement.
DARPA “One Shot” System to Have Wind-Reading Capability
Meanwhile, in the United States, the Defense Advanced Research Projects Agency (DARPA) is proceeding forward with a One-Shot Sniper System, another “Super-Scope” that will have day/night capability, and calculate both elevation AND windage correction automatically. Prototypes have already been tested, demonstrating that a laser beam can be used to “measure the average down-range crosswind profile”. The wind data is combined with readings of temperature, humidity, and target range to provide a very sophisticated ballistic solution. DARPA’s Spec for the One Shot program calls for a 12-42X Direct View Optic (DVO), a Riflescope Display Assembly (RDA), and an Integrated Spotting Scope (ISS) with rangefinder that ranges to 2 km, and provides “crosswind measurements”. The system will be “menu-selectable” for .308 Win, .338 Lapua, and .300 Win Mag. DARPA has budgeted big bucks for the One Shot system. The ISS, by itself, is expected to cost $85,000 per unit (for the first 15 units).
These systems will never replace the utility of an experienced shooter who possesses the skills of wind reading, but it is a real boon for less experienced shooters. In terms of military utility, it is a game changer. I’ve seen and used a prototype of the One Shot, and it does perform as advertised. — SFC Emil Praslick III, USAMU Coach
Can Wind-Reading Systems Work in the Real World?
From what we can tell, the LIDAR system, and America’s competing One Shot System, are both designed to measure crosswind speed and angle AT THE TARGET primarily. But as any experienced long-range shooter knows, wind is rarely constant along the entire path of the bullet. There can be a 10 mph left wind near the firing point, a 5 mph tailwind in mid-trajectory, and a 20 mph right wind 1000 yards away. Importantly, wind close to the shooter has more effect on the bullet’s path than wind far downrange — that’s a matter of simple geometry. Therefore, any wind-reading system could provide incorrect solutions if it is not able to read and calculate different wind vectors along the full bullet flight path. Presumably LIDAR and One Shot systems will attempt some kind of crosswind averaging, but that will be a very challenging task, without multiple wind sensors downrange.
Camera Land’s One-Penny Tripod Promo Camera Land is offering a Vortex $129.99 Ball-head Tripod for just one penny ($0.01) if you purchase a Vortex spotting scope from the product list below. Cameraland’s marketing team states: “We thought it would be a nice thing to offer a special deal to all those forum members who support us so we came up with a wonderful offer. If you buy any new Vortex Viper Spotter from the list below, for an extra $.01 we’ll include a Vortex Dakota Tripod (PN#-DKA) with a Ball Head.”
Get a Tripod for a Penny More
If you purchase a Vortex Viper or Vortex Razor Spotting scope from the about list, Camera Land will include a Vortex Dakota Tripod (PN#-DKA) with a Ball Head for just one penny more. The Dakota ball-head tripod currently sells for $129.99.
Sale tip from EdLongrange. We welcome reader submissions.
If you’re lucky enough to be able to attend the NRA Annual Meeting & Exhibits in St. Louis, stop by the Zeiss Booth (#1111) today or tomorrow. For NRA members on a mission to buy, Zeiss Sports Optics is offering special discounts on optics sold through an authorized retailer in the Zeiss booth during the show.
The Zeiss Conquest 3-9×40 riflescope (#20 reticle) will be available for only $399.00 and show attendees will also receive 10% off all other Zeiss products, except for the Victory RF and Victory FL 42mm binoculars. Zeiss already has a national consumer rebate promotion for the Victory RF binoculars ($300 rebate) and Victory FL 42mm binoculars ($200 rebate). NRA members who purchase a Victory RF or Victory FL 42mm binocular at the NRA show will instantly receive the rebate, on the spot. NRA Meeting attendees can also receive discounts on gear. Stop by the Zeiss booth, mention the Gear Store offer and you’ll receive a discount voucher for your purchase at ZeissGear.com. For more info on Zeiss optics, visit www.zeiss.com/sports or call 1-800-441-3005.
Zeiss Conquest 3-9x40mm
RifleScope with #20 Reticle.
Eurooptics.com now carries the impressive Vectronix Terrapin Laser Rangefinder. The $1995.00 Terrapin is a high-grade, milspec device rated to 2400m, well beyond the stated ranges for LRFs in the $600-$1000 class. Field reports indicated that the Terrapin is very good. One field tester, using a Terrapin set on a tripod, said the Terrapin hit 16″ plates at 800 yards more reliably than a Swarovski Laserguide. Ranging a small object like that at 800 yards is a tough test for any LRF. The Terrapin performs well on smaller objects because it has extremely tight beam divergence (this means the beam doesn’t spread out like a wide cone at long range).
The reports we’ve received indicate that the Vectronix lives up to expectations created by its 2400m distance rating. Jason Baney reports: “This Vectronics is impressive. In the right conditions, these units can range well beyond 2000 yards. On a Snipers’ Hide Thread, Vectronix Terrapin owners have reported ranging successfully past 3000 yards on large objects.” Available in tan or green, the Terrapin has a rugged aluminum inner housing and is rated to be waterproof with 60 minutes of immersion. It is easy to hold, and weighs just 1.1 pounds. Efficient electronics allow the Terrapin to make over 7,000 ranging “shots” before the two CR123 batteries need to be replaced.
Merit Corp. in Schenectady, NY, offers an adjustable metal diopter that attaches to shooting glasses with a rubber cup. Though primarily intended for pistol shooters, the Merit diopter can also be helpful when shooting rifles with open sights, such as military bolt actions. Priced at $65.00, the Merit device features a shutter-style adjustable aperture iris.
Merit explains: “The human eye, whether or not prescription glasses are required, cannot focus on both sights and the target at the same time. The eye will constantly shift focus from the sights to the target trying to ensure proper alignment. Unfortunately, as we age, the eye loses the flexibility which allows it to do this; thus, sights and target begin to grow fuzzy. There is a simple way to combat this by increasing your eyes’ depth of field (range of focus). If you look through an aperture or pinhole of the correct size, you will be able to see both sights clearly, and the target will be clearly defined as well.”
Forum member Roy Bertalotto did a real nice off-set scope installation on a bolt gun to help a sight-challenged shooter. Roy explains: “A friend of mine shoots left-handed and has lost the sight in his left eye. I built him a scope mount so he can still shoot left-handed, but now use his right eye.” Roy’s fabrication work is impressive and we praise his efforts to help a fellow shooter stay in the game.
Burris Signature Rings in Stock Again
The Reticle Compensating Rifle Barrel Reference Sensor takes the guesswork out of shooting by shifting the burden of knowing the relative position between the barrel and the weapon sight axes from the shooter to an electronic sensor. The system precisely measures the deflection of the barrel relative to the sight and then electronically realigns the moving reticle, or crosshairs, with the true position of the barrel, or bore axis.
The 
Imagine a “smart scope” that can range your target AND calculate windage correction. Such technology may appear in riflescopes fairly soon. The Israeli Government’s 
While the Israeli LIDAR system may seem like science fiction, it’s not that far removed from the lastest commercial optics. Engineers on both sides of the Atlantic have already integrated laser rangefinders (LRFs) into rifle-mounted “consumer” optics. Just this year, Burris introduced an affordable “consumer” scope, the 
Camera Land’s One-Penny Tripod Promo
If you’re lucky enough to be able to attend the NRA Annual Meeting & Exhibits in St. Louis, stop by the Zeiss Booth (#1111) today or tomorrow. For NRA members on a mission to buy, 
