Have you recently purchased a new scope? Then you should verify the actual click value of the turrets before you use the optic in competition (or on a long-range hunt). While a scope may have listed click values of 1/4-MOA, 1/8-MOA or 0.1 Mils, the reality may be slightly different. Many scopes have actual click values that are slightly higher or lower than the value claimed by the manufacturer. The small variance adds up when you click through a wide range of elevation.
In this video, Bryan Litz of Applied Ballistics shows how to verify your true click values using a “Tall Target Test”. The idea is to start at the bottom end of a vertical line, and then click up 30 MOA or so. Multiply the number of clicked MOA by 1.047 to get the claimed value in inches. For example, at 100 yards, 30 MOA is exactly 31.41 inches. Then measure the difference in your actual point of impact. If, for example, your point of impact is 33 inches, then you are getting more than the stated MOA with each click (assuming the target is positioned at exactly 100 yards).
How to Perform the Tall Target Test
The objective of the tall target test is to insure that your scope is giving you the proper amount of adjustment. For example, when you dial 30 MOA, are you really getting 30 MOA, or are you getting 28.5 or 31.2 MOA? The only way to be sure is to verify, don’t take it for granted! Knowing your scopes true click values insures that you can accurately apply a ballistic solution. In fact, many perceived inaccuracies of long range ballistics solutions are actually caused by the scopes not applying the intended adjustment. In order to verify your scope’s true movement and calculate a correction factor, follow the steps in the Tall Target Worksheet. This worksheet takes you thru the ‘calibration process’ including measuring true range to target and actual POI shift for a given scope adjustment. The goal is to calculate a correction factor that you can apply to a ballistic solution which accounts for the tracking error of your scope. For example, if you find your scope moves 7% more than it should, then you have to apply 7% less than the ballistic solution calls for to hit your target.
NOTE: When doing this test, don’t go for the maximum possible elevation. You don’t want to max out the elevation knob, running it to the top stop. Bryan Litz explains: “It’s good to avoid the extremes of adjustment when doing the tall target test.I don’t know how much different the clicks would be at the edges, but they’re not the same.”
Should You Perform a WIDE Target Test Too?
What about testing your windage clicks the same way, with a WIDE target test? Bryan Litz says that’s not really necessary: “The wide target test isn’t as important for a couple reasons. First, you typically don’t dial nearly as much wind as you do elevation. Second, your dialed windage is a guess to begin with; a moving average that’s different for every shot. Whereas you stand to gain a lot by nailing vertical down to the click, the same is not true of windage. If there’s a 5% error in your scope’s windage tracking, you’d never know it.”
Verifying Scope Level With Tall Target Test
Bryan says: “While setting up your Tall Target Test, you should also verify that your scope level is mounted and aligned properly. This is critical to insuring that you’ll have a long range horizontal zero when you dial on a bunch of elevation for long range shots. This is a requirement for all kinds of long range shooting. Without a properly-mounted scope level (verified on a Tall Target), you really can’t guarantee your horizontal zero at long range.”
NOTE: For ‘known-distance’ competition, this is the only mandatory part of the tall target test, since slight variations in elevation click-values are not that important once you’re centered “on target” at a known distance.
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New Technology — Electronic Reticle Level. Activate level by pushing illumination button for 15 seconds. The level warning deactivates automatically when you rotate the scope over 30 degrees.
The latest Leupold VX-6HD scopes have a feature we’d like to see incorporated in other optics: a tilt-correction warning system. When the rifle is canted more than 1 degree off level, the VX-6HD’s new electronic reticle level flashes, telling the shooter to square up his rifle. This kind of innovation helps both hunters and target shooters. Even a small bit of cant variance from shot to shot will change the point of impact at long range (Canting Demo HERE). Proprietary MST (Motion Sensor Technology) automatically deactivates illumination after 5 minutes of inactivity, yet reactivates instantly as soon as any movement is detected.
The electronic reticle level and other advanced VX-6HD features were praised by Petersen’s Hunting magazine, which awarded the VX-6HD an Editor’s Choice award. Leupold put a lot of advanced optics technology in this scope. Leupold says: “We gave it new high-definition lenses for sharpened clarity, Twilight Max Light Management System, an in-scope cant indicator, a throw lever for fast magnification changes, and a more robust erector system.”
Leupold offers six VX-6HD series riflescopes: 4-24x52mm, 3-18x50mm, 3-18x44mm, 2-12x42mm, 1-6x24mm, and 1-6x24mm multigun. All Leupold VX-6HD riflescopes are CDS-capable and include one free Custom Ballistic Dial with purchase.
The VX-6HD series of scopes also feature a very clever, button-controlled return-to-zero system for both windage and elevation. A visible button snaps out at the zero point, locking the turret. Press the ZeroLock button to release and dial your needed elevation or windage. Simply spin the turret back and the lock snaps into place automatically at the designated zero point. Simple, easy, effective.
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Hunters and tactical shooters need scopes with good low-light performance. For a scope to perform well at dawn and dusk, it needs good light transmission, plus a reasonably large exit pupil to make maximum use of your eye’s light processing ability. And generally speaking, the bigger the front objective, the better the low-light performance, other factors being equal. Given these basic principles, how can we quickly evaluate the low-light performance of different makes and models of scopes?
Here’s the answer: ScopeCalc.com offers a FREE web-based Low-Light Performance Calculator that lets you compare the light gain, perceived brightness, and overall low-light performance of various optics. Using this scope comparison tool is pretty easy — just input the magnification, objective diameter, exit pupil size, and light transmission ratio. If the scope’s manufacturer doesn’t publish an exit pupil size, then divide the objective diameter in millimeters by the magnification level. For example a 20-power scope with a 40mm objective should have a 2mm exit pupil. For most premium scopes, light transmission rates are typically 90% or better (averaged across the visible spectrum). However, not many manufacturers publish this data, so you may have to dig a little.
ScopeCalc.com’s calculator can be used for a single scope, a pair of scopes, or multiple scopes. Once you’ve typed in the needed data, click “Calculate” and the program will produce comparison charts showing Light Gain, Perceived Brightness, and Low-Light Performance. Though the program is easy to use, and quickly generates comparative data, assessing scope brightness, as perceived by the human eye, is not a simple matter. You’ll want to read the annotations that appear below the generated charts. For example, ScopeCalc’s creators explain: “Perceived brightness is calculated as the cube root of the light gain, which is the basis for modern computer color space brightness scaling.”
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At the 2018 NRA Show in Dallas last week, Trijicon unveiled a notable new scope that should interest Benchrest shooters and Long-Range competitors. The all-new Trijicon AccuPower 5-50x56mm Long Range Scope offers an impressive ten times zoom range, plus an illuminated reticle. This RS50 Series Second Focal Plane scope with 34mm main tube is offered in both MOA and MIL systems. The MOA version features 1/8 MOA clicks plus a reticle with 1 MOA subtensions at 40X power. The MIL version has 1/20 Milrad click values and a ranging style reticle with wind hold dot system. Both MOA and MIL versions have a full 100 MOA of elevation travel.
New Trijicon 5-50x56mm Scope Revealed at NRA Show in Dallas:
Credit Erik Cortina for providing this video.
With a $2700 MSRP, we expect Trijicon’s new 5-50X scope to have a “street price” of about $2400. That lines up with the NightForce 15-55x52mm Competition, now priced at $2352.00 on Amazon.
The new Trijicon 5-50x56mm (RS50 Series) scope boasts some nice features. Employing extra-low dispersion glass, the scope offers high light transmission with minimal chromatic aberration. The magnification control lever can be moved to two different positions to suit the operator. Both MOA and MIL reticle styles are illuminated with 5 red and 5 green user-selectable brightness settings.
We hope to get our hands on one of these new Trijicon 5-50X scopes soon for testing. We’ll let you know how it stacks up against other high-magnification zoom scopes, such as the Vortex 10-60x52mm Golden Eagle, the Nightforce 15-55x52mm, and the March 5-50x56mm.
Please note, along with this 5-50x56mm scope, Trijicon has also introduced a 4.5-30x56mm RS30 Series scope. This 4.5-30X optic will be offered in both First Focal Plane and Second Focal Plane versions. SEE AccuPower Scope Brochure.
Product Tip from EdLongrange. Video and Trijicon Brochure from Erik Cortina.
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SIG Sauer and Applied Ballistics showed off impressive new electro-optical technology at the NRA Show in Dallas. Bryan Litz says “SIG Sauer’s Ballistics Data Exchange (BDX) is game changer. Imagine lazing a long range target, and having your exact fire solution (hold-over) automatically projected into your scope based on your ballistic profile.”
BDX takes target range info from a SIG Sauer Laser Rangefinder, calculates a ballistic solution using Applied Ballistics software, then displays the hold-over info directly in the optic (via a wireless BlueTooth connection). Just dial and shoot. Put the calculated BDX dot on the target and shoot. This ground-breaking BDX technology enables key ballistic hold-over information to be exchanged wirelessly among BDX-enabled Electro-Optics products.
You can buy this as a package with scope and LRF, starting at just $700.00 for scope and rangefinder. To our surprise, these scopes have a normal form factor. They look completely “normal”, with no clunky receiver boxes or extra turrets. BDX riflescopes aren’t bulky or heavy even though they include built-in electronics, level, and inclination detection.
“Rangefinding riflescopes of the past have had two major shortcomings: they are either big, boxy and heavy, or extremely expensive. The … BDX system packs advanced ballistics technology into a simple platform that looks just like the rangefinder and riflescope [hunters use] today. It is extremely simple to use. Range a target, put the digital ballistic holdover dot on target, pull the trigger — just connect the dot.” — Andy York, President, SIG Sauer Electro-Optics.
SIG Sauer’s Ballistics Data Exchange (BDX) is an integrated system of devices that talk seamlessly to each other, sharing data. Applied Ballistics says this system be expanded in the months ahead. “This system will be comprised of scopes, rangefinders, binoculars, and more. BDX will even be able to ‘talk’ to Kestrels and Garmins as well as SIG Sauer smart-scopes. This is only the start, over the next year you will see increasing levels of tech becoming available.”
How BDX (Ballistics Data Exchange) Functions — Software and Hardware
How does BDX work? First download the SIG BDX App for Android or iOS. Then pair the KILO BDX rangefinder and SIERRA3BDX riflescope, and set up a basic ballistic profile. Once you are in the field, range your target as you normally would, and the KILO BDX rangefinder will utilize onboard Applied Ballistics Ultralight™ to instantly send your dope to the scope via Bluetooth. Using your basic ballistic profile, the ballistic solution is calculated for your target and will instantly illuminate on the BDX-R1 Digital Ballistic Reticle with windage and elevation holds in the SIERRA3BDX riflescope. A blue LED on the riflescope power selector indicates that the BDX system is paired, and when the reticle has received new ballistic holdover and windage data from the rangefinder.
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This helpful video from our friend Kirsten Joy Weiss explains how to avoid “scope bite”. This can occur when the scope, on recoil, moves back to contact your forehead, brow, or eye socket area. That’s not fun. While common sense tells us to avoid “scope bite” — sooner or later this happens to most shooters. One viewer noted: “I have come close. I had a Win Model 70 in .375 H & H Mag and I was shooting over a large rock in a strange position. The scope hit my eye glasses hard enough to bend the wire frames and cause a little pain on the bridge of the nose from the nose piece. [That] made a believer out of me.”
Kirsten offers a good basic principle — she suggests that you mount your rifle-scope so that the ocular (eyepiece) of the scope is positioned at least three inches or more from your eyeball when you hold the rifle in your normal shooting position. From a technical standpoint, optical eye relief is a property of the scope, so you want to purchase an optic that offers sufficient optical eye relief (meaning that it allows you to see the full circle of light with your head at least three inches from the eyepiece). Then you need to position the optic optimally for your head/eye position when shooting the rifle — with at least three inches of eyeball-to-scope separation (i.e. physical eye relief).
NOTE: You should mount the scope to provide adequate eyeball-to-scope separation for the actual position(s) you will be shooting most of the time. For an F-TR rig, this will be prone. For a hunting rifle, your most common position could be sitting or standing. Your head position will vary based on the position. You can’t assume the scope placement is correct just because it seems OK when you are testing or zeroing the gun from the bench. When shooting from a prone or kneeling position you may find your eye considerably closer to the eyepiece.
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PRS guys — check this out. Kahles has just announced a 5-25X First Focal Plane optic that should be a class leader. If you are thinking of upgrading your tactical scope this year, the new Kahles K525i should definitely be on any “short list” of ultra-premium optics. We predict this will be one of the top-performing tactical scopes on the market. Unfortunately, it will also be one of the most expensive. Kahles lists the K525i at €3,300.00 Euros. That’s $4,093.58 at current exchange rates! You can buy a pair of pretty nice tactical rifles for that. Hopefully Kahles will consider dropping the price a bit for the American market. Don’t know how many PRS guys are willing to fork over four grand for a scope.
Thankfully, it looks like the true “street price” in the USA will be a lot lower. EuroOptic.com is now taking pre-orders for the K525i at $3,299.00 USD — that’s a lot different than the €3,300.00 Euro MSRP. Kahles says the scopes should start arriving in summer 2018.
This scope is available in both Mil and MOA versions. Click values are 0.1 MIL, or 1/4 MOA. A variety of illuminated, First Focal Plane (FFP) reticles are offered: SKMR3, SKMR, MSR2, Mil4+, MOAK. Notably the parallax control is coaxial with the elevation turret (meaning it is centrally mounted). You adjust parallax by rotating a large-diameter control that runs around the base of the elevation turret. We know that south-paws really like that feature.
Kahles also offers two windage configurations. You can have the windage mounted on either side — on the left side for right-handed shooters or on the right side for left-hand shooters. The windage knob also features a patented “Twist Guard” rotating end cover, which is easy to control while preventing accidental windage rotation.
Manufacturer’s Product Description
K527i features: Maximum optical performance-field of vision, contrast and picture quality, Exceptional repeat accuracy, precise and clearly defined turret mechanism 0.1 MIL or 1⁄4 MOA, side adjustment left or right, Parallax wheel integrated in the elevation turret, patented TWIST GUARD windage, precise illuminated reticles in the first focal plane and large adjustment range.
“The big brother of ultrashort K318i is the new flagship of KAHLES in the field of tactical riflescopes. It combines … maximum optical performance and highest precision with unique handling and ergonomics. The rugged K525i, with its practical magnification range, has been developed for tactical use and long distances.”
PRODUCT HIGHLIGHTS
.: Maximum optical performance — field of vision, contrast, and picture quality
.: Exceptional repeat accuracy
.: Precise and clearly-defined click mechanism 0.1 MIL, MRAD or ¼ MOA
.: Side adjustment left or right
.: Parallax wheel integrated in the elevation turret (patented) for 20m – infinity
.: Innovative, patented TWIST GUARD windage
.: Precise illuminated reticles in first focal plane: SKMR3, SKMR, MSR2, Mil4+, MOAK
.: Large adjustment range with 2.9m (E) and 1.3m (W) at 100m
.: Zero Stop
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A varmint shooter’s target is not conveniently placed at a fixed, known distance as it is for a benchrester. The varminter must repeatedly make corrections for bullet drop as he moves from closer targets to more distant targets and back again. Click HERE to read an interesting AccurateShooter Varrmint Forum discussion regarding the best method to adjust for elevation. Some shooters advocate using the scope’s elevation adjustments. Other varminters prefer to hold-over, perhaps with the assistance of vertical markers on their reticles. Still others combine both methods–holding off to a given yardage, then cranking elevation after that.
Majority View — Click Your Elevation Knob
“I zero at 100 yards — I mean really zero as in check the ballistics at 200 and 300 and adjust zero accordingly — and then set the scope zero. For each of my groundhog guns I have a click chart taped into the inside of the lid of the ammo box. Then use the knobs. That’s why they’re there. With a good scope they’re a whole lot more accurate than hold-over, with or without hash marks. This all assumes you have a good range finder and use it properly. If not, and you’re holding over you’re really just spraying and praying. Try twisting them knobs and you’ll most likely find that a 500- or 600- or 700-yard groundhog is a whole lot easier than some people think.” – Gunamonth
“I have my elevation knob calibrated in 100-yard increments out to 550. Range-find the critter, move elevation knob up…dead critter. The problem with hold-over is that it is so imprecise. It’s not repeatable because you are holding over for elevation and for wind also. Every time you change targets 50 yards, it seems as if you are starting over. As soon as I got completely away from the hold over method (I used to zero for 200), my hit ratios went way up.” — K. Candler
“When I first started p-dog shooting, I attempted to use the hold-over method with a 200-yard zero with my 6mm Rem. Any dog much past 325-350 yards was fairly safe. I started using a comeups table for all three of my p-dog rifles (.223 Rems and 6mm Rem). 450-yard hits with the .223s are fairly routine and a 650-yard dog better beware of the 6mm nowadays. An added benefit (one I didn’t think of beforehand) with the comeups table (elevation only), is that when the wind is blowing, it takes half of the variables out of the equation. I can concentrate on wind, and not have to worry about elevation. It makes things much more simple.” — Mike (Linefinder).
“I dial for elevation and hold for wind. Also use a mil-dot reticle to make the windage holds easier. For windage corrections, I watch for the bullet strike measure the distance it was “off” with the mil-dot reticle, then hold that much more the other way. Very fast once you get used to it.” — PepeLP
Minority View–Hold-Over is Better
“I try to not touch my knobs once I’m zeroed at 200 meters. Most of my varmint scopes have duplex reticles and I use the bottom post to put me on at 300 meters versus turning knobs. The reason I try to leave my knobs alone is that I have gone one complete revolution up or down [too far] many times and have missed the varmint. This has happened more than once and that is why I try not to change my knobs if at all possible.” — Chino69
“I have been using the hold over method and it works for me most of the time but the 450 yards and over shots get kinda hard. I moved to a 300 yard zero this year and it’s working well. I do want to get into the click-up method though; it seems to be more fool-proof.” — 500YardHog
Compromise View–Use Both Methods
“I use both [methods] as well — hold over out to 250, and click up past that.” — Jack (Wolf)
“I use the target knobs and crank-in elevation. I also use a rangefinder and know how far away they are before I crank in the clicks. I have a scope with drop dots from Premier Recticle and like it. No cranking [knobs] out to 600.” –Vmthtr
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Riflescopes are mechanical contraptions. One of the sad realities about precision shooting is that, sooner or later, you will experience a scope failure. If you’re lucky it won’t happen in the middle of a National-level competition. And hopefully the failure will be dramatic and unmistakable so you won’t spend months trying to isolate the issue. Unfortunately, scope problems can be erratic or hard to diagnose. You may find yourself with unexplained flyers or a slight degradation of accuracy and you won’t know how to diagnose the problem. And when a 1/8th-MOA-click scope starts failing, it may be hard to recognize the fault immediately, because the POI change may be slight.
When An Expensive Scope Goes Bad
A few seasons back, this editor had a major-brand 8-25x50mm scope go bad. How did I know I had a problem? Well the first sign was a wild “drop-down” flyer at a 600-yard match. After shooting a two-target relay, I took a look at my targets. My first 5-shot group had five shots, fairly well centered, in about 2.2″. Pretty good. Everything was operating fine. Then I looked at the second target. My eye was drawn to four shots, all centered in the 10 Ring, measuring about 2.4″. But then I saw the fifth shot. It was a good 18″ low, straight down from the X. And I really mean straight down — if you drew a plumb line down from the center of the X, it would pass almost through the fifth shot.
Is My Scope Actually Malfunctioning or Is This Driver Error?
That was disconcerting, but since I had never had any trouble with this scope before, I assumed it was a load problem (too little powder?), or simple driver error (maybe I flinched or yanked the trigger?). Accordingly, I didn’t do anything about the scope, figuring the problem was me or the load.
Even expensive scopes can fail, or start to perform erratically — and that can happen without warning, or for no apparent reason. Here are some signs that you may be having scope issues.
1. Click count has changed signficantly from established zero at known range.
2. Noticeably different click “feel” as you rotate turrets, or turrets feel wobbly.
3. Inability to set Adjustable Objective or side focus to get sharp target image.
4. Shot Point of Impact is completely different than click value after elevation/windage change. For example, when you dial 2 MOA “up” but you observe a 6 MOA rise in POI.
Problems Reappear — Huge POI Swings Affirm This Scope is Toast
But, at the next range session, things went downhill fast. In three shots, I did manage to get on steel at 600, with my normal come-up for that distance. Everything seemed fine. So then I switched to paper. We had a buddy in the pits with a walkie-talkie and he radioed that he couldn’t see any bullet holes in the paper after five shots. My spotter said he thought the bullets were impacting in the dirt, just below the paper. OK, I thought, we’ll add 3 MOA up (12 clicks), and that should raise POI 18″ and I should be on paper, near center. That didn’t work — now the bullets were impacting in the berm ABOVE the target frame. The POI had changed over 48″ (8 MOA). (And no I didn’t click too far — I clicked slowly, counting each click out loud as I adjusted the elevation.) OK, to compensate now I took off 8 clicks which should be 2 MOA or 12″. No joy. The POI dropped about 24″ (4 MOA) and the POI also moved moved 18″ right, to the edge of the target.
For the next 20 shots, we kept “chasing center” trying to get the gun zeroed at 600 yards. We never did. After burning a lot of ammo, we gave up. Before stowing the gun for the trip home, I dialed back to my 100-yard zero, which is my normal practice (it’s 47 clicks down from 600-yard zero). I immediately noticed that the “feel” of the elevation knob didn’t seem right. Even though I was pretty much in the center of my elevation (I have a +20 MOA scope mount), the clicks felt really tight — as they do when you’re at the very limit of travel. There was a lot of resistance in the clicks and they didn’t seem to move the right amount. And it seemed that I’d have four or five clicks that were “bunched up” with a lot of resistance, and then the next click would have almost no resistance and seem to jump. It’s hard to describe, but it was like winding a spring that erratically moved from tight to very loose.
At this point I announced to my shooting buddies: “I think the scope has taken a dump.” I let one buddy work the elevation knob a bit. “That feels weird,” he said: “the clicks aren’t consistent… first it doesn’t want to move, then the clicks jump too easily.”
Convinced that I had a real problem, the scope was packed up and shipped to the manufacturer. So, was I hallucinating? Was my problem really just driver error? I’ve heard plenty of stories about guys who sent scopes in for repair, only to receive their optics back with a terse note saying: “Scope passed inspection and function test 100%. No repairs needed”. So, was my scope really FUBAR? You bet it was. When the scope came back from the factory, the Repair Record stated that nearly all the internal mechanicals had been replaced or fixed: “Replaced Adjustment Elevation; Replaced Adjustment Windage; Reworked Erector System; Reworked Selector; Reworked Parallax Control.”
How to Diagnose Scope Problems
When you see your groups open up, there’s a very good chance this is due to poor wind-reading, or other “driver error”. But my experience showed me that sometimes scopes do go bad. When your accuracy degrades without any other reasonable explanation, the cause of the problem may well be your optics. Here are some of the “symptoms” of scope troubles:
1. Large shot-to-shot variance in Point of Impact with known accurate loads.
2. Uneven tracking (either vertical or horizontal).
3. Change of Point of Impact does not correspond to click inputs.
4. Inability to zero in reasonable number of shots.
5. Unexpected changes in needed click values (compared to previous come-ups).
6. Visible shift in reticle from center of view.
7. Changed “feel” or resistance when clicking; or uneven click-to-click “feel”.
8. Inability to set parallax to achieve sharpness.
9. Turrets or other controls feel wobbly or loose.
10. Internal scope components rattle when gun is moved.
Source of Problem Unknown, but I Have a Theory
Although my scope came with a slightly canted reticle from the factory, it had otherwise functioned without a hitch for many years. I was able to go back and forth between 100-yard zero and 600-yard zero with perfect repeatability for over five years. I had confidence in that scope. Why did it fail when it did? My theory is side-loading on the turrets. I used to carry the gun in a thick soft case. I recently switched to an aluminum-sided hard case that has pretty dense egg-crate foam inside. I noticed it took some effort to close the case, though it was more than big enough, width-wise, to hold the gun. My thinking is that the foam wasn’t compressing enough, resulting in a side-load on the windage turret when the case was clamped shut. This is just my best guess; it may not be the real source of the problem. Remember, as I explained in the beginning of this story, sometimes scopes — just like any mechanical system — simply stop working for no apparent reason.
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The Swarovski Optik website features a blog with interesting technical articles. In the “On Target” series of blog stories, Swarovski has provided a handy explanation of how optics systems work, with exploded diagrams of rifle scopes, spotting scopes, and binoculars. CLICK HERE for Swarovski Optics Blog.
Scope Terminology Focusing Lens
The focusing lens is an adjustable lens inside the optical system for focusing the image at different distances…. In the case of rifle scopes, apart from focusing, the focusing lens also facilitates parallax compensation.
Diopter Adjustment
For rifle scopes, the reticle can be focused using the diopter adjustment on the eyepiece, thereby correcting any visual impairment. [Editor’s Note: Movable eyepiece diopter adjustment is not offered on all rifle scopes. It is a useful feature on Swarovski and other premium scopes. This allows shooters who need eyeglasses to get a sharply focus image even without wearing corrective lenses. Of course shooters should always wear ANSI-certified eye protection. With the diopter, folks who need correction can use inexpensive, non-Rx safety eyewear instead of expensive prescription safety glasses.]
Reversal System
The purpose of the reversal system is to reverse the image by means of prisms in binoculars and telescopes, and lenses in rifle scopes….The lens reversal system is needed in rifle scopes to control the variable magnification and move the exit pupil[.]
Parallax Explained
What is Parallax? What problems can Parallax create when you are shooting? Many novice shooters can’t answer those questions easily. Likewise, many folks don’t understand how to use their front or side-focus parallax controls most effectively. Yes the parallax control basically sharpen focus at different target distances — but there’s more involved. This video offers helpful insights.
Resource tip by EdLongRange. We welcome reader submissions.
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Do you find that the crosshairs in your scope get blurry after a while, or that you experience eye strain during a match? This is normal, particularly as you get older. Focusing intensely on your target (through the scope or over iron sights) for an extended period of time can cause eye strain. Thankfully, there are things you can do to reduce eye fatigue. For one — breathe deeper to take in more oxygen. Secondly, give your eyes a break between shots, looking away from the scope or sights.
In our Forum there is an interesting thread about vision and eye fatigue. One Forum member observed: “I have noticed recently that if I linger on the target for too long the crosshairs begin to blur and the whole image gradually darkens as if a cloud passed over the sun. I do wear contacts and wonder if that’s the problem. Anyone else experienced this? — Tommy”
Forum members advised Tommy to relax and breath deep. Increase oxygen intake and also move the eyes off the target for a bit. Closing the eyes briefly between shots can also relieve eye strain. Tommy found this improved the situation.
Keith G. noted: “Make sure you are still breathing… [your condition] sounds similar to the symptoms of holding one’s breath.”
Phil H. explained: “Tom — Our eyes are tremendous oxygen hogs. What you are witnessing is caused by lack of oxygen. When this happens, get off the sights, stare at the grass (most people’s eyes find the color green relaxing), breath, then get back on the rifle. Working on your cardio can help immensely. Worked for me when I shot Palma. Those aperture sights were a bear! The better my cardio got the better and longer I could see. Same thing with scopes. Try it!”
Watercam concurred: “+1 on breathing. Take a long slow deep breath, exhale and break shot. Also make sure you take a moment to look at the horizon without looking through rifle or spotting scope once in a while to fight fatigue. Same thing happens when using iron sights.”
Arizona shooter Scott Harris offered this advice: “To some extent, [blurring vision] happens to anyone staring at something for a long time. I try to keep vision crisp by getting the shot off in a timely fashion or close the eyes briefly to refresh them. Also keep moisturized and protect against wind with wrap-around glasses”.
Breathing Better and Relaxing the Eyes Really Worked…
Tommy, the shooter with the eye problem, said his vision improved after he worked on his breathing and gave his eyes a rest between shots: “Thanks guys. These techniques shrunk my group just a bit and every little bit helps.”
Read more tips on reducing eye fatigue in our Forum Thread: That Vision Thing.
To avoid eye fatigue, take your eyes away from the scope between shots, and look at something nearby (or even close your eyes briefly). Also work on your breathing and don’t hold your breath too long — that robs your system of oxygen.
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Review by James Mock
If you were charged with building a scope for F-Class or long range Benchrest, what features would you want? Vortex asked that question, received feedback from many competitors, and then set out to build a new high-magnification, zoom comp scope that would set a new “performance for price” standard.
The new Vortex Golden Eagle has features that this shooter really appreciates. It has a power range of 15x to 60x with a 52mm objective lens. Vortex has attempted to keep the weight as low as possible and the cost reasonable. My initial impression is that Vortex spared no expense in developing this scope. The “street price” for this premium scope is a reasonable $1499.00. Plus it has Unconditional Lifetime Warranty. Given its features, performance, and price, I believe that this scope will sell very well.
Premium HD, extra-low dispersion glass
APO (apochromatic) objective lens system with index-matched lenses
XRP multi-coated lenses for max light transmission
ArmorTek extra-hard lens coating to protect lens from dust, dirt, and smudges
Fogproof and Waterproof (Argon gas purged)
Specifications
Field of View at 100 yards: 6.3 feet at 15X; 1.7 feet at 60X
Main Tube: One-piece 30mm
Length: 16.1 inches; Weight is 29.7 ounces
Objective Lens: 52mm
Eye Relief: 3.9 inches
Reticles: SCR-1 FCH; ECR-1 MOA
Testing the Golden Eagle
I recently tested a Golden Eagle with the ECR-1 reticle. On this model the Hash Marks subtend 1 MOA at 40X. There is also a fine crosshair reticle (SCR-1) available. Initial tests with the scope were done on June 28th and I was very impressed with what I saw. With a new scope I always shoot the square (box test) to test tracking and amount of movement. I shot the square today after shooting a 5-shot group at 250 yards (my longest available distance). Below is a picture of the box test target that I shot. Yes, shot #5 went through the exact same hole as shot #1.
Below is the 250-yard target I shot before doing the box test. To get to the 100-yard target, I clicked down 14 clicks (1/8th MOA) and the scope was spot on. It is really a pleasure to use instruments that do exactly what they are supposed to do. With the Louisiana mirage, I shot this orange/white target at 40X instead of the maximum 60X. I did not have any problem seeing the 6mm bullet holes at 40X. The optics in this scope are to my old eyes are as good as any that I have used (regardless of price).
Competition Test Success — Golden Eagle Delivers a Win
My next use of this scope was at our monthly 600-yard match on July 15th. It was a typical mid-July day in north Louisiana — very hot and humid with light switching winds. The mirage was terrible, but I managed to squeak out a victory with a 188/5X score out of 200/20X possible. I shot the Golden Eagle at 40X all day and it performed perfectly. No one could see bullet holes today, even with the high powered premium spotting scopes. This is a quality scope and it may be a “lucky” scope in that I did not expect a win with a 6mm Dasher barrel with 2500 or more rounds through it.
Point of Aim Test with Hood Scope Checker
I also tested the Golden Eagle for holding Point of Aim (POA). For this procedure, I used the Hood scope checker (loaned to me by Bart Sauter). To use this, one mounts two scopes side by side. Ideally one scope has proven its ability to hold POA. Here I used a Valdada 36X BR model as my control scope. It has proven over an 8-year period of time to hold its point of aim. I mounted these scopes on my BAT/Leonard 6mm PPC and adjusted each to the same point on the target.
As one can see in the above picture, these are big scopes. After the first shot, I noticed that the reticle dot on the Vortex seemed to be about 1/8th MOA to the right of its original position. I stopped to check for ring slippage (which I had experienced in prior tests). There was no apparent slippage, so I checked the parallax and found that there was some parallax correction needed. This was probably the source of the apparent shift in point of aim, but I cannot be sure of that. I fired three more shots (checking after each) and found no shift.
After testing for POA shift, I fired the remaining rounds using different aiming points. I fired 5 rounds (upper left) using the Vortex and 3 rounds to the right of those using the Valdada scope.
CONCLUSION — A Very Fine Optic at a Reasonable Price
While testing this Vortex Golden Eagle scope, I developed a real fondness for it. I appreciate its great optics, eye relief and crispness of adjustments. If I thought that this scope did not hold POA, I would use my old Valdada in the 600-yard matches in which I participate. Further testing has shown no tendency to shift point of aim.
If I am allowed to keep this scope until the fall, I am sure that I will be able to see 6mm bullet holes in the white at 600 yards. Seeing those 6mm holes is very difficult, but that is my dream for a premium high-powered scope. During the summer months in north Louisiana, the air is much too “dirty” to spot small holes at 600 yards. By October, there should be some conditions in which one can use the premium optics to see bullet holes in the white at 600.
In summary, let me say that this scope has become one of my all-time favorites because of its bright, clear images and its great reliability. If you are looking for a great long-range scope that is reasonable in cost, try the Golden Eagle from Vortex.– James Mock
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Verifying Scope Level With Tall Target Test
The electronic reticle level and other advanced VX-6HD features were praised by Petersen’s Hunting magazine, which awarded the VX-6HD an Editor’s Choice award. Leupold put a lot of advanced optics technology in this scope. Leupold says: “We gave it new high-definition lenses for sharpened clarity, Twilight Max Light Management System, an in-scope cant indicator, a throw lever for fast magnification changes, and a more robust erector system.”
Hunters and tactical shooters need scopes with good low-light performance. For a scope to perform well at dawn and dusk, it needs good light transmission, plus a reasonably large exit pupil to make maximum use of your eye’s light processing ability. And generally speaking, the bigger the front objective, the better the low-light performance, other factors being equal. Given these basic principles, how can we quickly evaluate the low-light performance of different makes and models of scopes?
This scope is available in both Mil and MOA versions. Click values are 0.1 MIL, or 1/4 MOA. A variety of illuminated, First Focal Plane (FFP) reticles are offered: SKMR3, SKMR, MSR2, Mil4+, MOAK. Notably the parallax control is coaxial with the elevation turret (meaning it is centrally mounted). You adjust parallax by rotating a large-diameter control that runs around the base of the elevation turret. We know that south-paws really like that feature.
A varmint shooter’s target is not conveniently placed at a fixed, known distance as it is for a benchrester. The varminter must repeatedly make corrections for bullet drop as he moves from closer targets to more distant targets and back again. 
Minority View–Hold-Over is Better
For the next 20 shots, we kept “chasing center” trying to get the gun zeroed at 600 yards. We never did. After burning a lot of ammo, we gave up. Before stowing the gun for the trip home, I dialed back to my 100-yard zero, which is my normal practice (it’s 47 clicks down from 600-yard zero). I immediately noticed that the “feel” of the elevation knob didn’t seem right. Even though I was pretty much in the center of my elevation (I have a +20 MOA scope mount), the clicks felt really tight — as they do when you’re at the very limit of travel. There was a lot of resistance in the clicks and they didn’t seem to move the right amount. And it seemed that I’d have four or five clicks that were “bunched up” with a lot of resistance, and then the next click would have almost no resistance and seem to jump. It’s hard to describe, but it was like winding a spring that erratically moved from tight to very loose.
Competition Test Success — Golden Eagle Delivers a Win
