Let’s say you’ve purchased a new scope, and the spec-sheet indicates it is calibrated for quarter-MOA clicks. One MOA is 1.047″ inches at 100 yards, so you figure that’s how far your point of impact (POI) will move with four clicks. Well, unfortunately, you may be wrong. You can’t necessarily rely on what the manufacturer says. Production tolerances being what they are, you should test your scope to determine how much movement it actually delivers with each click of the turret. It may move a quarter-MOA, or maybe a quarter-inch, or maybe something else entirely. (Likewise scopes advertised as having 1/8-MOA clicks may deliver more or less than 1 actual MOA for 8 clicks.)
Reader Lindy explains how to check your clicks: “First, make sure the rifle is not loaded. Take a 40″ or longer carpenter’s ruler, and put a very visible mark (such as the center of an orange Shoot’N’C dot), at 37.7 inches. (On mine, I placed two dots side by side every 5 inches, so I could quickly count the dots.) Mount the ruler vertically (zero at top) exactly 100 yards away, carefully measured.
Place the rifle in a good hold on sandbags or other rest. With your hundred-yard zero on the rifle, using max magnification, carefully aim your center crosshairs at the top of the ruler (zero end-point). Have an assistant crank on 36 (indicated) MOA (i.e. 144 clicks), being careful not to move the rifle. (You really do need a helper, it’s very difficult to keep the rifle motionless if you crank the knobs yourself.) With each click, the reticle will move a bit down toward the bottom of the ruler. Note where the center crosshairs rest when your helper is done clicking. If the scope is accurately calibrated, it should be right at that 37.7 inch mark. If not, record where 144 clicks puts you on the ruler, to figure out what your actual click value is. (Repeat this several times as necessary, to get a “rock-solid”, repeatable value.) You now know, for that scope, how much each click actually moves the reticle at 100 yards–and, of course, that will scale proportionally at longer distances. This optical method is better than shooting, because you don’t have the uncertainly associated with determining a group center.
Using this method, I discovered that my Leupold 6.5-20X50 M1 has click values that are calibrated in what I called ‘Shooter’s MOA’, rather than true MOA. That is to say, 4 clicks moved POI 1.000″, rather than 1.047″ (true MOA). That’s about a 5% error.
I’ve tested bunches of scopes, and lots have click values which are significantly off what the manufacturer has advertised. You can’t rely on printed specifications–each scope is different. Until you check your particular scope, you can’t be sure how much it really moves with each click.
I’ve found the true click value varies not only by manufacturer, but by model and individual unit. My Leupold 3.5-10 M3LR was dead on. So was my U.S.O. SN-3 with an H25 reticle, but other SN-3s have been off, and so is my Leupold 6.5-20X50M1. So, check ‘em all, is my policy.”
From the Expert: “…Very good and important article, especially from a ballistics point of view. If a ballistics program predicts 30 MOA of drop at 1000 yards for example, and you dial 30 MOA on your scope and hit high or low, it’s easy to begin questioning BCs, MVs, and everything else under the sun. In my experience, more than 50% of the time error in trajectory prediction at long range is actually scope adjustment error. For serious long range shooting, the test described in this article is a MUST!” — Bryan Litz, Applied Ballistics LLC.
Bryan also uses a Tall Target Test to determine true click values. CLICK HERE to read a detailed, explanatory article about Litz’s Tall Target Test.
This article, as published in AccurateShooter.com, contains copyrighted content. It shall not be republished in whole or in part without advanced permission in writing. The act of republishing constitutes legal consent to licensing fees.
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Let’s say you’ve purchased a new scope, and the spec-sheet indicates it is calibrated for quarter-MOA clicks. One MOA is 1.047″ inches at 100 yards, so you figure that’s how far your point of impact (POI) will move with four clicks. Well, unfortunately, you may be wrong. You can’t necessarily rely on what the manufacturer says. Production tolerances being what they are, you should test your scope to determine how much movement it actually delivers with each click of the turret. It may move a quarter-MOA, or maybe a quarter-inch, or maybe something else entirely. (Likewise scopes advertised as having 1/8-MOA clicks may deliver more or less than 1 actual MOA for 8 clicks.)
Reader Lindy explains how to check your clicks: “First, make sure the rifle is not loaded. Take a 40″ or longer carpenter’s ruler, and put a very visible mark (such as the center of an orange Shoot’N’C dot), at 37.7 inches. (On mine, I placed two dots side by side every 5 inches, so I could quickly count the dots.) Mount the ruler vertically (zero at top) exactly 100 yards away, carefully measured.
Place the rifle in a good hold on sandbags or other rest. With your hundred-yard zero on the rifle, using max magnification, carefully aim your center crosshairs at the top of the ruler (zero end-point). Have an assistant crank on 36 (indicated) MOA (i.e. 144 clicks), being careful not to move the rifle. (You really do need a helper, it’s very difficult to keep the rifle motionless if you crank the knobs yourself.) With each click, the reticle will move a bit down toward the bottom of the ruler. Note where the center crosshairs rest when your helper is done clicking. If the scope is accurately calibrated, it should be right at that 37.7 inch mark. If not, record where 144 clicks puts you on the ruler, to figure out what your actual click value is. (Repeat this several times as necessary, to get a “rock-solid”, repeatable value.) You now know, for that scope, how much each click actually moves the reticle at 100 yards–and, of course, that will scale proportionally at longer distances. This optical method is better than shooting, because you don’t have the uncertainly associated with determining a group center.
Using this method, I discovered that my Leupold 6.5-20X50 M1 has click values that are calibrated in what I called ‘Shooter’s MOA’, rather than true MOA. That is to say, 4 clicks moved POI 1.000″, rather than 1.047″ (true MOA). That’s about a 5% error.
I’ve tested bunches of scopes, and lots have click values which are significantly off what the manufacturer has advertised. You can’t rely on printed specifications–each scope is different. Until you check your particular scope, you can’t be sure how much it really moves with each click.
I’ve found the true click value varies not only by manufacturer, but by model and individual unit. My Leupold 3.5-10 M3LR was dead on. So was my U.S.O. SN-3 with an H25 reticle, but other SN-3s have been off, and so is my Leupold 6.5-20X50M1. So, check ‘em all, is my policy.”
From the Expert: “…Very good and important article, especially from a ballistics point of view. If a ballistics program predicts 30 MOA of drop at 1000 yards for example, and you dial 30 MOA on your scope and hit high or low, it’s easy to begin questioning BCs, MVs, and everything else under the sun. In my experience, more than 50% of the time error in trajectory prediction at long range is actually scope adjustment error. For serious long range shooting, the test described in this article is a MUST!” — Bryan Litz, Applied Ballistics for Long-Range Shooting.
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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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Reader Lindy explains how to check your clicks: “First, make sure the rifle is not loaded. Take a 40″ or longer carpenter’s ruler, and put a very visible mark (such as the center of an orange Shoot’N’C dot), at 37.7 inches. (On mine, I placed two dots side by side every 5 inches, so I could quickly count the dots.) Mount the ruler vertically (zero at top) exactly 100 yards away, carefully measured.
Reader Lindy explains how to check your clicks: “First, make sure the rifle is not loaded. Take a 40″ or longer carpenter’s ruler, and put a very visible mark (such as the center of an orange Shoot’N’C dot), at 37.7 inches. (On mine, I placed two dots side by side every 5 inches, so I could quickly count the dots.) Mount the ruler vertically (zero at top) exactly 100 yards away, carefully measured.
Competition Test Success — Golden Eagle Delivers a Win
