SIG Sauer used to only be known for their excellent line of semi-automatic handguns, and then they branched out into the battle rifle and long rifle categories and we even reviewed their updated version of the SIG SSG3000 sniper rifle. Now over the last couple of years we have watched SIG blossom into a full spectrum manufacturer that includes laser range finders, such as the Kilo 2000, ammunition, combat optics and more. What we have decided to review here is one of their new high end Tango 6 line of tactical rifle scopes. For their optics, SIG offers the Whiskey line for hunters and the Tango line for tactical use. If you have not yet noticed, they have adopted the military phonetic alphabet to distinguish their various lines of optics with Kilo, Whiskey, Tango, Echo, Oscar and others now being used. For our review here we brought in their top of the line Tango 6 scope in 3-18x44mm guise with first focal plane reticle which has a MSRP of $2160. We have been pleased with just about every SIG product we have tested in the past, so it was time to see how they did with an upper tier tactical rifle scope.
The scope comes in a sturdy and well made scope box with a few basic accessories. The provided accessories include a bikini style lens cover, two different hex (Allen) wrenches, an instruction manual, battery for the illuminated reticle and a coupon for a free SBT (SIG Ballistic Turret) which is a BDC knob that SIG will mark to your specifications. The instruction manual follows the same well written pattern as their other instruction manuals found with their other products. It includes some well drawn images to show how the various controls work on the scope as well as how to perform other operations on the scope such as setting the zero stop. It is not a large or thick manual, but it does a good job doing what it is supposed to.
Flipping the scope over and looking on the bottom, there is some writing that indicates the scope was “Designed by SIG Sauer in Oregon” and then it indicates the scope was assembled in Japan. There are a number of nice higher end scopes made in Japan such as the Nightforce NXS, so the country of origin should not be an issue provided one of the high end manufacturers was used. The eyepiece on the scope is somewhat large but the scope itself, with a 30mm tube and smaller 44mm objective, is not what we would consider large. There is a fast focus eyepiece with a hard rubber end on it that should not be as damaging to skin should the shooter have their eye too close and receive a scope kiss during recoil. The fast focus eyepiece rotates a total of about 1.6 revolutions as it spans its full dioptre adjustment range when adjusting the focus of the reticle. There is a moderate amount of resistance when rotating the dioptre adjustment which should hold the eyepiece in place once set. There is a nice green tick mark on the hard rubber itself that gives the operator a good reference point when using the scope with multiple shooters, but as is the case with all fast focus eyepieces, there is no locking ring.
At the front of the eyepiece is located the zoom power adjustment ring where the operator selects the magnification they would like the scope set to. This ring has very aggressive knurling on it and provides excellent grip in all weather conditions. The “6” part of the Tango 6 designation indicates that the scope has a zoom range of six, this model going from 3x to 18x. The eyepiece has white markings on it with various zoom powers marked along the way. The markings are on a flat part of the eyepiece and are not angled toward the operator, so you do have to raise your head a bit to see the number the scope is set at. There are two parallel protrusions on the zoom ring with high visibility green optical identifiers that bracket the zoom number. It is a different way of doing it and it works well, though the operators head still needs to be raised to see what number those indicators are bracketing. This particular scope has the reticle in the first focal plane (FFP) so the magnification setting does not matter, but SIG has several models of the same scope with reticles in the second focal plane (SFP) where the magnification setting does matter. The zoom ring itself has about the right mount of friction to it to hold it nicely in place, yet it is not too stiff to make adjusting it difficult. The ring also rotates very smoothly through its entire range.
In front of the zoom ring the large eyepiece tapers down quickly to the 30mm wide aluminum tube where there is just a tad over two inches of mounting area for the scope mounting ring. The shoulder of the scope where the elevation and windage controls are located is not overly large and has a nicely rounded shape. The elevation knob is a tall knob with knurling at the top that takes about half of the marking area of the knob, but again, the knurling provides a very nice gripping surface in all weather conditions. The knob also pushes down to lock it in place to prevent the knob from rotating until it is pulled up where it can then operate as a normal knob does.
There are some other scopes that have this same style locking setup and it is not a bad design as it can prevent the knobs from accidentally being rotated while moving or even when doing routine stuff in your FFP, but we would not consider it a ‘must have’ option. Each click of the knob is .25 MOA of adjustment and there is a full 20 MOA per revolution which allows a 308 Win 175gr rifle to go from 100 to 1000 yards in just under two full rotations of the knob. When the knob is in its lifted position there are horizontal lines beneath the knob to help keep track of what rotation the knob is on. There is also an adjustable zero stop that can be set to your zero in case if you do loose track of what rotation you are on. SIG indicates that there are 72 MOA of adjustment from the factory and with the zerostop set all the way to the bottom of our test scope there was 73 MOA available on this sample. Combined with a 20 MOA canted base this is enough for long range shooting, though perhaps not enough for extreme range engagements. The clicks themselves are nicely muted with no slop or mushiness at all, which is to be expected on a higher end scope. Though we noticed the tactile clicks are a bit soft, especially when wearing gloves. There is resistance at each click and you can still feel the clicks if you pay attention, but perhaps a little more tactile indication to the clicks would make them perfect.
The windage knob is the same shape as the elevation knob though it is about .25″ shorter. It also has the same locking function as the elevation knob does and the same aggressive knurling. The numerical lettering on both knobs is a bit small, but it is clear and sharp and easy enough to read from behind the scope. The numbering on the windage knob counts up in both directions and with 20 MOA of adjustment the overlap happens right at 10 MOA allowing for a rifle shooting 308 Win 175gr ammo to shoot in a 10 MPH direct crosswind past 1000 yards in standard atmospheric conditions before the overlap in numbering occurs. There is a direction indicator lower on the shoulder of the windage knob but the numbering on the knob itself does not indicate which direction of adjustment you have dialed in. On both the elevation and windage knobs there are three set screws that need to be loosened to “slip the knobs” and set them to zero. To set the zero stop on the elevation knob the process is more involved and requires removing the knob, then removing another adjustment shroud with a different size Allen wrench (that is why two wrenches are provided) and then spinning and adjusting the zero stop to where you want it. It takes some effort, but is not something that needs to be set too often. Just set it about 2-3 MOA below your actual zero and that should provide some fudge factor for slight zero adjustments while clearly indicating when you are at the bottom.
On the opposite side of the scope from the windage knob is the parallax adjustment and reticle illumination controls. They rotate freely of each other and we will talk about each of them separately. The parallax, or focus knob is located closest to the scope tube and has the same style of knurling as the other control knobs. It is marked from 25 yards to 300 yards and then a final marking for infinity. The full range of adjustment is only about half of a rotation which makes the adjustment not as fine as perhaps it could be with a control that utilizes more rotation than just half of a turn. It does rotate smoothly and has enough resistance to nicely keep it in place once set.
On ‘top’ of the focus knob is located the illumination controls. As was mentioned, it rotates separately from the focus knob and has detentes for each brightness setting as well as an off setting between each of the brightness levels. Having an off setting between each brightness level allows for the illumination to be turned off right next to the desired brightness level that the operator chooses and is the preferred way of doing it instead of making the operator go through all of the other brightness settings to turn it on or off. The markings indicate the brightness level by the size of a little square box. This is a bit different and makes it difficult to remember a particular setting for a given condition like a number would allow you to do, but that is not a huge deal and it works well enough. There are ten brightness setting that cover a wide range of brightness levels including some very low settings that will likely be used the most. There is also one setting that is specific for use with night vision devices and is marked “IR”. This is an excellent idea and was a nice feature to see with the continued popularity of forward mounted night vision devices. With the control being stacked on top of the focus knob it means there might be an occasional accidental turning of the illumination control, but it did not seem to be a problem during our use and the scope also has an “inactive” feature that turns the reticle off if no movement is detected for a period of time and then immediately turns it back on when the scope is again moved. This will help save the batteries if the illuminated reticle is accidentally left on.
In front of the shoulder of the scope there is a bit more than 2.5″ of tube length to mount the forward scope ring and then the tube tapers up into the forward bell. The very front part of the bell bevels down ever so slightly which gives the impression that the scope is not setup to use a forward mounted sunshade, but it is threaded and technically could accept one. Though checking out the SIG web page does not show that one is currently offered from SIG. Hopefully that will change at some point. The overall size and shape of the scope is pleasing enough, though it appears that the eyepiece is nearly as large as the objective bell on this particular scope. The finish on the scope is a matte grey anodizing that is unique and different from the traditional matte black and while some here at Sniper Central were not sure how it would look on any number of different colored rifles, it turns out that it blends in fine. The finish is nicely applied and the overall fit and finish of the scope is excellent.
We would not consider the Tango-6 in this configuration to be a large scope though it does weighs almost exactly 2 pounds which can be a lot if you are trying to keep your rifle package trim for lugging around the woods. After poking and prodding the scope and examining all the details we needed to test and see how the scope does operationally on top of a rifle. We used a set of Leupold Mk4 30mm medium height rings to mount the scope to a Steyr SSG-04 that was chambered in .308 Winchester. The bolt handle on the SSG-04 extends about a half inch out before it bends down and this extra little distance made it so that the bolt handle would lightly rub against knurling of the zoom ring on the eyepiece of the scope. It did not impede operation of the rifle in any way, but it did eventually produce a light wear mark on the bolt handle of the rifle. We fitted the scope to a Remington 700 and there was no issue at all with plenty of room between the bolt handle and the eyepiece. On an our all black SSG-04 rifle the scope ended up matching very well with its black accents and the package had a pleasing overall appearance.
For our testing the weather was good old fashioned Montana winter weather with plenty of snow and temperatures in the twenties. The operational tests were mostly conducted wearing gloves which did highlight the softer tactile feel of the clicks on the elevation and windage knobs. While the clicks were precise, we would just like a more tactile feel to them. If you are unfamiliar with how we test our scopes, please take a moment to read our “how we test rifles and scopes” page.
When we ran the scope through the box test it did very well with the adjustments controlling the point impact precisely and with very good repeatability. The size of the box was the appropriate size so we moved on to our click adjustment size test. We fired one very tight sub .5 MOA group and then dialed in 20 MOA of left and fired the next group, which again was nice and tight at just over .5 MOA. Finally we dialed 20 MOA of right back into the scope and fired the third group which was right on top of the first one. This verified that the repeatability was again excellent and when we measured the groups they ended up being 20.93″ apart. At 100 yards 20 MOA equals 20.94″ making the error a minuscule 0.05%, in essence, there was no error. So it was obvious that the precision was well within our accepted 3% of error due to group size and shooter error.
With this version of the Tango 6 the reticle is located on the first focal plane and with a full 6x of zoom range from 3-18x, it can be a difficult task to make the reticle thick enough to be seen at the lower power settings yet not too thick to be imprecise when zoomed all the way in to 18x. The MOA Milling reticle does a nice job with this balance. The reticle is configured in MOA to make it match up with the MOA knobs and it consists of larger and smaller hash marks for the various MOA measurements. At the lower magnification levels the smaller hash marks do disappear as you can see in the picture above where the scope was set on about 8x. As the magnification is zoomed in a small center dot also becomes visible which was handy for precision aiming at higher magnifications. As is probably appropriate, only the center portion of the reticle where the hash marks are located is illuminated.
The optics and glass quality one the scope are very good, as would be expected for the price category that the scope is slotted in and also coming from one of the high quality manufacturing plants in Japan. The picture is bright and sharp from edge to edge with good contrast and the optics compare very well with its expected competitors. It is difficult to rate or grade optical quality beyond some side by side comparisons, of which it did well.
We next had to test for reticle drift with both the zoom function and the focus knob. With our bore sighting device mounted and the scope dialed in, we started with the zoom ring. We adjusted the power from 3x up to 18x and back down to 3x several times to watch and see if the reticle moved at all. We were pleased to see that it is rock solid through the range. When we shifted to the parallel adjustment, or focus knob, we set the scope to 10x as this gave us a good reticle size we could easily and precisely see in the scope on the bore sighting grid. We then ran the focus ring all the way from the very bottom of the focus range (25 yards) up to infinity and back down several times. As we moved the knob through the entire range we did notice a slight drifting of the reticle in an up and slightly right direction, call it the 1 O’clock position. Reticle movement is not uncommon on scopes, especially scopes with a side focus, as there are so many moving parts on the inside of these optical devices. The total movement constituted about 1-2 MOA total through the whole range. Because the full adjustment range of the focus knob happens on only about half of a revolution of the knob, a majority of that reticle drift happens from the 25-100 yard portion of the knob. At the practical distances this scope would be used for (100-infinity) the amount of movement is much smaller and while we like to see no reticle movement at all, this is likely an acceptable amount and we did not notice any drastic shifts of bullet impacts when utilizing the scope at longer distances.
For a first offering from a new player in the tactical scope market, we commend SIG Sauer for developing a scope that has some unique features and is a well designed and made scope. We found just a few things we didn’t like such as the not so firm clicks and a slightly wandering reticle when adjusting the parallax and we would like to see some more vertical adjustment. But overall the scope is solid and should serve well on a long range duty rifle. The Tango 6 does find itself priced against some stiff competition in its price range from the likes of Nightforce, US Optics Bravo Series, high end Bushnell Tactical scopes, and Leupold. But the quality is good and there are enough differences that it should stand up to the competition well.
Sniper Central
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Outstanding article!
Quality matters where Vortex scopes and signature optics have a special place in the heart of hunters. It’s amazing to see how SIG Sauer has developed from a company best known for handguns to a full-service producer of a wide range of weapons and accessories. Their diversification and innovation dedication are demonstrated by their foray into other products like battle optics, ammo, and laser range finders. Specifically, the attention you paid to evaluating the premium Tango 6 series of tactical rifle scopes illuminates SIG’s commitment to quality across a range of industries. This is a very helpful review. Thanks.