May 27th, 2019

TECH Tip: How to Verify Your Scope’s True Click Values

Click Optics MOA turrent verification test

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.)

Nightforce scope turretReader 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.

Permalink Optics, Tech Tip 9 Comments »
March 26th, 2019

Angular Measurement — Mil vs. MOA — What You Need to Know

Mil MOA reticle ranging PRS tactical minute angle precision rifle series
Visit PrecisionRifleBlog.com for a discussion of MIL vs. MOA.

Many guys getting started in long range shooting are confused about what kind of scope they should buy — specifically whether it should have MIL-based clicks or MOA-based clicks. Before you can make that decision, you need to understand the terminology. This article, with a video by Bryan Litz, explains MILS and MOA so you can choose the right type of scope for your intended application.

This March-FX 5-40x56mm Tactical FFP scope features 0.05 MIL Clicks.
Mil MOA reticle ranging PRS tactical minute angle precision rifle series

You probably know that MOA stands for “Minute of Angle” (or more precisely “minute of arc”), but could you define the terms “Milrad” or “MIL”? In his latest video, Bryan Litz of Applied Ballitics explains MOA and MILs (short for “milliradians”). Bryan defines those terms and explains how they are used. One MOA is an angular measurement (1/60th of one degree) that subtends 1.047″ at 100 yards. One MIL (i.e. one milliradian) subtends 1/10th meter at 100 meters; that means that 0.1 Mil is one centimeter (1 cm) at 100 meters. Is one angular measurement system better than another? Not necessarily… Bryan explains that Mildot scopes may be handy for ranging, but scopes with MOA-based clicks work just fine for precision work at known distances. Also because one MOA is almost exactly one inch at 100 yards, the MOA system is convenient for expressing a rifle’s accuracy. By common parlance, a “half-MOA” rifle can shoot groups that are 1/2-inch (or smaller) at 100 yards.

What is a “Minute” of Angle?
When talking about angular degrees, a “minute” is simply 1/60th. So a “Minute of Angle” is simply 1/60th of one degree of a central angle, measured either up and down (for elevation) or side to side (for windage). At 100 yards, 1 MOA equals 1.047″ on the target. This is often rounded to one inch for simplicity. Say, for example, you click up 1 MOA (four clicks on a 1/4-MOA scope). That is roughly 1 inch at 100 yards, or roughly 4 inches at 400 yards, since the target area measured by an MOA subtension increases with the distance.

one MOA minute of angle diagram

MIL vs. MOA for Target Ranging
MIL or MOA — which angular measuring system is better for target ranging (and hold-offs)? In a recent article on his PrecisionRifleBlog.com website, Cal Zant tackles that question. Analyzing the pros and cons of each, Zant concludes that both systems work well, provided you have compatible click values on your scope. Zant does note that a 1/4 MOA division is “slightly more precise” than 1/10th mil, but that’s really not a big deal: “Technically, 1/4 MOA clicks provide a little finer adjustments than 1/10 MIL. This difference is very slight… it only equates to 0.1″ difference in adjustments at 100 yards or 1″ at 1,000 yards[.]” Zant adds that, in practical terms, both 1/4-MOA clicks and 1/10th-MIL clicks work well in the field: “Most shooters agree that 1/4 MOA or 1/10 MIL are both right around that sweet spot.”

READ MIL vs. MOA Cal Zant Article.

Permalink - Articles, - Videos, Shooting Skills 6 Comments »
March 24th, 2017

Verify Your TRUE Scope Click Values with Tall Target Test

Scope Click Verify Elevation Tall Target Bryan Litz NSSF test turret MOA MIL

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).

Scope Click Verify Elevation Tall Target Bryan Litz NSSF test turret MOA MIL

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.


CLICK HERE to DOWNLOAD Tall Target Worksheet (PDF)

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.”

Scope Tall Test level calibrationVerifying 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.

Permalink Optics, Tech Tip No Comments »
January 13th, 2017

How to Use Mil-Dot Scope Reticles to Estimate Range

NRA Video Milrad MIL mil-dot range reticle

MIL-system scopes are popular with tactical shooters. One advantage of MIL scopes is that the mil-dot divisions in the reticle can be used to estimate range to a target. If you know the actual size of a target, you can calculate the distance to the target relatively easily with a mil-based ranging reticle. Watch this helpful NRA video to see how this is done:

(more…)

Permalink - Videos, Optics 5 Comments »
August 23rd, 2015

New Screw-On Knurled Dials for Leupold Scope Turrets

Leupold Stevens scope turret windage elevation dial optic MIL MOA replacement accessory cap aluminum
New S1 and S5 Knurled Dials can be user-installed in place of older Leupold turret caps.

Leupold & Stevens makes good scopes, but the standard turrets with screw-on caps are inconvenient for some users. It’s too easy to misplace the caps. Also the standard turrets are not the easiest to grip, particularly with gloved hands. To improve the “gripability” of its scope turrets, Leupold now offers new S1 and S5 screw-on knurled dials that fit in place of the cap covers. These aluminum dials offer large, knurled surfaces that are easy to grip, even when wearing gloves. “These screw-on dials mean no more lost caps or the need for a coin to make adjustments in the field,” said Tim Lesser, Leupold’s Product Development Director. The S1 is for MOA scopes while the S5 is for MIL scopes.

Leupold Stevens scope turret windage elevation dial optic MIL MOA replacement accessory cap aluminum

The S1 and S5 dials simply replace Leupold’s screw-on turret caps, so the user can install these easily without tools. It is NOT necessary to send your scope(s) back to the factory. Just remove the caps on your windage and elevation turrets, and screw the knurled dials in their place. The S1/S5 dials automatically align with the adjustment slot and securely tighten down. These dials are interchangeable between different riflescopes in the field. MSRP is $50 per dial set (either S1 or S5).

The S1 dial is engraved in ¼-MOA increments while the S5 (for mil-based turrets) is marked in 0.1 MIL. Both come with a locking zero stop and can be equipped with the Custom Dial System® (CDS) through the Leupold Custom Shop. The Leupold S1 and S5 dials are compatible with most Leupold riflescopes with click adjustments, with the exception of the VX-1 series and older riflescopes with friction adjustments. For those with bullet-drop-compensating reticles, the S1 and S5 are completely compatible. The screw on dials are covered by Leupold’s full lifetime guarantee.

Permalink New Product, Optics 13 Comments »
October 7th, 2014

MIL vs. MOA Reticles — Which Are Better for Tactical Tasks?

MIL or MOA — which angular measuring system is better for target ranging (and hold-offs)? In a recent article on his PrecisionRifleBlog.com website, Cal Zant tackles that question. Analyzing the pros and cons of each, Zant concludes that both systems work well, provided you have compatible click values on your scope. Zant does note that a 1/4 MOA division is “slightly more precise” than 1/10th mil, but that’s really not a big deal: “Technically, 1/4 MOA clicks provide a little finer adjustments than 1/10 MIL. This difference is very slight… it only equates to 0.1″ difference in adjustments at 100 yards or 1″ at 1,000 yards[.]” Zant adds that, in practical terms, both 1/4-MOA clicks and 1/10th-MIL clicks work well in the field: “Most shooters agree that 1/4 MOA or 1/10 MIL are both right around that sweet spot.”

Mil MOA reticle ranging PRS tactical minute angle precision rifle series

READ MIL vs. MOA Cal Zant Article.

Zant does note that a whopping 94% of shooters in the Precision Rifle Series (PRS) used a mil-based reticle. However, Zant says: “This does NOT mean MIL is better. It just means MIL-based scopes are more popular.” Zant agrees with Bryan Litz’s take on the subject: “You can’t really go wrong with either (MIL or MOA). They’re both equally effective, it comes down to how well you know the system. If you’re comfortable with MOA, I wouldn’t recommend switching to MIL. I have a few MIL scopes but primarily because they’re on rifles used for military evaluation projects, and that community is now mostly converted to MILS, so when in Rome….”

We recommend you read Zant’s complete article which is very thorough and is illustrated with helpful graphics. Here are the key points Zant makes in his MIL vs. MOA analysis:

MIL vs. MOA — Key Points
There are a handful of minor differences/trade-offs between MIL & MOA, but there are no inherent advantage to either system. Most people blow the small differences WAY out of proportion….Here are the biggest differences and things to keep in mind:

  • Whatever you decide, go with matching turret/reticle (i.e. MIL/MIL or MOA/MOA)
  • 1/4 MOA adjustments are slightly more precise than 1/10 MIL.
  • MIL values are slightly easier to communicate.
  • If you think in yards/inches the math for range estimation is easier with MOA. If you think in meters/cm the math is easier with MIL.
  • When your shooting partners are using one system, there can be some advantage to having the same system.
  • Around 90% of the PRS competitors use MIL.
  • There are more product options (with ranging reticles) in MIL.

Range Card Print-Outs
Zant makes an interesting practical point regarding range card print-outs. He suggests the MIL System may be easier to read: “You can see in the range card examples below, 1/4 MOA adjustments take up more room and are a little harder to read than 1/10 MIL adjustments.”

mil vs moa reticle scope

Permalink Optics, Tactical 11 Comments »
October 3rd, 2014

Swarovski’s New 80mm Spotting Scope Offers Illuminated Reticle

STR 80 Swarovski Spotting scope with ReticleSwarovski has a new STR 80 spotting scope with an illuminated reticle. That’s right, this new STR 80 spotter has a ranging reticle like a riflescope, with adjustable brightness levels. This 80mm spotting scope can be used for estimating range to targets, using MIL-based or MOA-based stadia lines on the cross-hairs. This allows you to range targets optically, as you could with a ranging reticle in a riflescope.

Revolutionary Reticle “ON”, Reticle “OFF” Technology
The STR 80’s illuminated ranging reticle makes the new STR 80 a fairly unique product among high-end, imported spotting scopes. Thanks to a new technology, Swarovski is the first manufacturer to successfully project a reticle directly in a spotting scope. The reticle (MOA or MRAD) can be activated or deactivated as required. Notably, because the reticle appears via electro-illumination, it can be “turned off” for un-obstructed viewing. So you can have a totally clear field of view when desired, OR a ranging reticle when that functionality is desired. Having the ability to turn OFF the reticle is great — that’s a very intelligent feature.

STR 80 Swarovski Spotting scope with Reticle

When viewing targets, the STR 80’s sharp HD (high-definition) lenses will resolve bullet holes at long range. Current Swaro 20-60X and 25-50X (wide) eyepieces can be used with the new STR 80 spotter. Optional accessories include Picatinny mounting rail, digiscoping attachment, and a winged eye cup.

How to Range with STR 80 Reticles
The new STR 80 scope offers a choice of either MOA or MRAD reticles with 15 brightness levels, 10 day levels, and 5 night levels. For convenient ranging, set the magnification level so that the MOA reticle displays ¼ MOA divisions, while the MRAD Reticle displays 0.1 MIL divisions. (NOTE: the reticle will change in size relative to the target at different magnifcation levels. Therefore ranging is normally done at one standard magnification level).

STR 80 Swarovski Spotting scope with Reticle

Dustin Woods, Sales Director for Swarovski Optik NA said: “Long range shooters asked for a premium spotting scope with integrated reticle and we have listened. With our new STR spotting scope we now have MOA and Mil-Radian reticle models. Because the reticle is illuminated, the user can have the reticle turned on when they are judging hits and misses but also turn it completely off for an unobstructed view during observation. This product is a real game changer in the precision shooting segment.”

Permalink New Product, Optics 5 Comments »