Zeiss V6 5-30x50 ZBR & Sako A7 Roughtech Pro 308Win - English version

long range shooting, riflescope -

Zeiss V6 5-30x50 ZBR & Sako A7 Roughtech Pro 308Win - English version

This article written primarily for hunters. Article reviews interesting products and explains basic information about reticles, sight adjustments and procedures needed for longer shooting ranges.

 

Suomenkielinen versio täällä - Finnish version here

 

Guns, ammunition and ballistic apps have gone forward big leaps. Traditionally perhaps the most difficult puzzle to solve for precision shooters has been accurate field-usable ballistic solver, but this problem too has been history for few years already. As Finnish offerings, both Lapua and Sako have their versions and they are also free to use. Finnaccuracy has own in-house ballistic engine, but it is not publicly available.

As sensible shooting ranges extend, also optics will have to evolve bit further than having just coin-adjustable turret under cap. Turrets are still somewhat mystical for some old-school hunters. For instance: If rifle zero is ok one should not touch anything. If one still touches turret, rifle zero should absolutely be re-checked by shooting. But in reality these days are long gone, at least what comes to optics in decent quality category. Open turrets are actually designed intentionally so that they can be cranked back and forth countless times, mercy is not needed at all. If turret is adjusted and then returned back to its original position, also group will follow without any additional checks. If not, scope is broken or something else in setup is wrong. This is a fact with any decent quality modern riflescope.

Zeiss V6 5-30x50 in this review is one of scopes made to meet these modern standards. Scope has been offered for a while for American shooters already, and is now coming to Europe/Finland as well. We are also happy to offer this V6 model very soon. Zeiss adds also V6 3-18 to European selection same time, also these already visible in our webshop V6 section

 

Turrets

Also 5-30 Zeiss has open turrets, which are getting more and more popularity among bird hunters and range shooters. Turrets are somewhat light to turn, but practical feedback is still pretty good. They are less crisp compared to military scopes, but still good enough to guarantee clear feedback of adjusted click amount. This is not always the case with hunting category scopes. V6 turrets will not lock and elevation does not have zero stop. Turrets are MOA- based, 0.25 MOA per click. MOA or "minute of angle" is angular system just like any other, but are still  minute-of-jargon to many European hunters.Translated to familiar metric system, each click will shift reticle 7.3mm at 100m distance. Not 7.6mm or 8.1mm, but 7.3mm. Strange uneven millimeter amount may stop some readers bubblegum chewing, but truth is that you will get along with them fine - as long as very basics of angular system are known. And basics are not that difficult really, actually straight forward if one thinks it trough. For instance. Most mobile ballistic applications will clearly inform user how many clicks each turret should be turned, and also to which direction. If application settings are selected to MOA -system with 0.25MOA clicks, then they are presented that way in firing solution as well. Only remaining thing to do is to read numbers from screen and set same numbers to turrets. Done! Bullet doesn't care about unit engraved in turret- and according to Finnaccuracy Labs research department this will also not effect on earth gravity or even surrounding air molecule movements. Bullet always fly same so only thing needed is to compensate impact point with known unit clicks. How ever, centimeter (milliradian) click system still make life easier in situations where metric corrections needs to be solved fast without calculator. For instance: Click that moves point of impact 1cm at 100meters (=0.1mrad), moves it 2cm@200m, 3cm@300m, 6.5cm@650m or 9.234cm@923.4m. Respectively with 0.25 MOA clicks as is the with this particular Zeiss too, one click shifts impact 7.3mm@100m, 14.6mm@200m, 21.9mm@300m and 47.45mm@650m. Strange uneven numbers, but process is still very straight forward as result is simply multiplication of one hundred meter shift by desired longer distance in hectometers. MOA- system scope can also be zeroed just as conveniently: required shift click amount is shift divided by one click effect in same distance. In practice, required click amount can be checked with ruler measure and any mobile phone calculator in few seconds.

Reticle

Zeiss 5-30 reticles are not illuminated and they are always located in second focal plane (SFP). When view trough SFP scope is increased or decreased by zooming, reticle appears to be always same size. Respectively, if image size changes and reticle size not, then reticle relative size to target/view has to change in direct relation with magnification ratio. If reticle dimensions are intended to be used for aiming points or for other purposes, dimensions will have to be valid and to be known precisely. Consequence is that magnification has to be exactly correct in order to use reticle for any sensible shooting- excluding simple center cross aiming naturally. Zeiss V6 ZBR reticle has been originally designed to be MOA scale. This magical sweet-spot happens on magnification 25x, and this is also engraved between zoom ratio numbers with dot. When magnification mark is aligned precisely with this dot, reticle dimensions can be used as MOA- base and they also match perfectly with turret 0.25 MOA clicks (each one MOA hashmark equaling four clicks). Angular dimensions (MOA or milliradian) are also not changing with distance. If shooter is zeroing rifle and spots impacts, say, 2 hashmarks low, it is 2MOA low (1+1 hashmarks) - as long as magnification is set at 25x. Turret shifts impact 0.25 MOA with each click, so therefore 8 clicks is needed to shift impact on exactly desired point. At any distance. Milliradian - or "centimeter" -scaled reticles and clicks work with same principle, no further calculations needed at all.

 

SFP reticle "zoom scaling" can also advantage sometimes, and Zeiss ZBR reticle happens to be textbook example about it. As mentioned, ZBR scaling is originally intended to be with 1MOA deviation (1MOA = 2.91cm/100m). If and when magnification is increased above MOA - calibration magnification 25x, image grows and therefore reticle shrinks relatively. When 28.5x is achieved (with this individual scope), hashmark deviation is exactly 25mm at 100meter, or in another words, 0.25mrad.  Most interesting part from shooting point of view is vertical hairline below center cross, line that is used for hold-over aiming. This hairline has 5 stepped width horizontal lines and space between each is divided into 4 equal segments. Deviation between wide horizontal lines is  (1mrad 4x0.25mrad) and 5 wide lines offer possibility to aim 5mrad high. This is very handy in further processing when ballistic software mrad drops are used as aiming points for longer ranges. Clear, simple and precise for both hold-overs and offs - as long as magnification is correct!  If magnification should be cranked down because of mirage for instance, mrad scale is not valid anymore. Available open turrets are still handy and precise secondary way to shift reticle in any situation, and this Zeiss makes this possible too.  If reticle is used for shooting described way, it is good policy to check dimensions from each individual scope. Zoom mechanism play can be checked same time. Play may cause variation to reticle size depending if magnification is turned to preset value from larger or smaller zoom. Zeiss did not have this problem- or it was too small see by sensible means. 

 

100m (109yd) zero targets. Reticle set to milliradian scaling with 28.5x magnification. Also secondary zero point 2.5mrad up explained. This is needed for direct hold-overs at app. 650yd and beyond, depending about bullet and muzzle velocity.

Zeiss ZBR reticle scaled to mrad

 

Rifle

Sako disassembled to its main components. Roughtech aluminum skeleton peeking inside rear part of stock action inlay. Rear action bolt is tightened trough frame.  Test rifle under reviewed Zeiss was one of Sako's late models, stainless A7- series Roughtech Pro in caliber 308 Win. I looked forward to this test, because I do not shoot with light hunting rifles too often. First feel after taking rifle in hand was, well, light. After playing with it a minute, roughtech texture felt still good. It is very grippy but still does not feel coarse or sandpaper-like at all. Second instant observation was overall stiffness combined to stock light weight. Aluminum skeleton inside surely stiffens it compared to typical stock, and overall feel is surprisingly similar when handling rifle with carbon fiber stock. Hard and light, but very stiff. Roughtech stock surface has countless amount of very small lumps. Idea is to offer good grip in all conditions, and it seems to work. We also had questionable honor to have plenty of test time it in rain and cold, soaking wet gloves included. It worked. Internet is full of happy owner stories about Sako hunting rifle accuracy, and for once I had change to witness it myself too. Accuracy was surprisingly close to actual tac-drivers, and this with factory loads from shelf. Rather expensive Lapua precision ammunition, but still. This rifle was not new and had unknown amount of shots behind. Preparations begun with intensive cleaning and copper removal. My new favorite Boretech Elimininator did the job with trusted Dewey rods  + jags without breaking a sweat. Also scope was mounted and zeroed with collimator. Sako trigger is clean braking single-stage, measured 1350g or 3lbs as it was adjusted by Sako factory. Harris BRM-S bipod (6-9") was mounted to sling stud as well.

 

Its clean! And no machining mishaps visible. Throat/neck eyeballed to be on center relatively to bore. This is not always the case with mass-produced barrels.

 

Roughtech texture under FA Labs special analysis. Photo, close-up photo and microscope photo.

 

 


 

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To zeroing!

Couple of first shots at 100m zero range were sacrificed to get impacts close to center cross. Third and fourth were already very close to aiming mark and very first 3-shot group right after was already promising. Sako magazine holds 3 rounds and barrel is thin (17mm/0.67" from muzzle), so we decided to go with 3-shot groups during actual test. Test ammunition was Lapua Scenar OTM 167gr/10.85g. Somebody told me long time ago that "if 167gr Scenar wont group, rifle is cursed" - and luckily this rifle wasn't either. Vice versa actually.

During six test groups rain intensified. Momentarily rain was so bad we had to take pauses, aiming mark couldn't be seen clearly. Rifle was still not cooled intentionally, excluding one longer brake when targets were checked. Already during first target check trip trend seemed to be that groups get tighter along shooting. This was probably because barrel was settling down after complete copper removal. Groups tightened, but also group location change eased down along shooting. Although this could be casued partially by shooter too, rifle felt very different to what I usually use. Bit stiffer single-stage trigger felt odd after 1kg/2lbs two-stages, especially with soaking-wet gloves and cold fingers. 2 shots were sent prematurely in beginning, but not later anymore. Trigger is good enough not limiting rifle performance - and I personally do not like light triggers anyway. Final result was very good 0.63MOA or 18.5mm/0.73" average with 6x3 shots. As trend was, very last group was best with 10mm/0.39" size = 0.34MOA. Remaining turret travel up after turret zero was 14.75MOA or 4.4mrad. Velocities were measured with Labradar, all shots averaging 804m/s or 2638fps. This velocity was also used in ballistic calculations later during actual LR test. Each shot during both zero trip and later test shooting were shot with allegedly worlds smallest ear-safe Ase Utra SL5i -suppressor and Harris -bipod. Beanbag under buttstock was used during zero trip, but not on actual longer range shooting. Somebody forgot to take bag from office table, but luckily fists were not left behind. They were also used, as probably most of hunters do it anyway so no real harm done. Long range precision and especially first round hits are all about preparation and having systematical approach on variable elimination. Muzzle velocity and bullet ballistics have to be precisely known to hit. Radar is one very good way to measure velocities. Microwave beam is insensitive to light amount/direction and rifle barrel does not need any attached sensors, so point of impact can not be effected even theoretically.

 

First and last group.

 

 

 

 

Field test                    

Expectations were high after promising zeroing trip. Poor plates seemed doomed to be bombarded, at least up to maximum 700m range to where we could adjust scope. Shooting was decided to be done by using reticle only, set on 28.5x to make it match milliradian dimensions. Steel plates at 506m and 631m (553yd and 690yd) were 45x45cm (17.7"x17.7") At 721m (788yd) plate was same width, but bit taller. Everything was set, except weather did unpleasant trick again with fog and light rain. Fog did not block visibility in beginning, but was still thick enough to disable even excellent Vectronix PLRF-10C laser. It stalled showing only max 140m distance reflection. Ranging was done with GPS only, in this case with handy Tracker map software. Tracker application is supporting both GPS and Glonass- satellites simultaneously so very likely distance error was less than 5 meters or 5 yards. Probably 1...3m. Fog kept intensifying during shooting, and unfortunately we had to pack sooner than planned. Luckily we still managed to get enough shots to draw final conclusions about both scope and rifle. Scope optical quality helps seeing trough mirage, but it also helps with fog. Good contrast is needed to see smallest tone differences in big white haze. Besides struggle with pure seeing, also some reticle-related phenomenons were witnessed. Such weather having just right amount of fog to be in edge of visibility is rare, but reticle can play surprisingly big role in such situation. Clear areas of view must be used to find objects, and then reticle is shifted on top of it- few times back and forth to be sure. Simple hairline cross will not interfere too much, but ZBR (or any similar) structure with lots of markings shifted on top of barely visible object made aiming impossible: object shape is lost instantly. Exactly same phenomenon can happen in twilight too by the way, and it doesn't really matter if reticle is illuminated or not. Zeiss V6 5-30 image quality was consireded already during rainy pauses of zero trip. Feeling got stronger during this trip: in practice only feature giving V6 away against much more expensive V8 flagship- series is field of view.  In another hand, 5-30 magnification without illumination means is meant for bird hunters or range shooters and FOV does not really play big role in such use. FOV is also typical in its class, Swarovski Z6i 5-30 FOV is almost same. V6 is assembled around previous Victory- line FL lenses, so image has nice contrast besides of resolution.

 Still visible, soon not so well.. This phone adapter can stand real recoil, made by  G-Line.

 

506m/556yd. Shot and impact ding. Flight time to target 0.8 seconds. Impact sound returning takes about 1.6 seconds.

 

Aiming

 

All shooting was made directly with reticle. We did not touch turrets at all with two closer ranges 506m and 631m (553yd and 690yd). Lapua free ballistic application shows needed aiming point to compensate both wind and drop. Reticle on mobile screen seem much different compared to ZBR layout, but is in fact with same milliradian scaling. In mobile application, longer hashmarks are with 1mrad deviation, shorter lines are half milliradian marks. Zeiss ZBR hashmark deviation is denser 0.25mrad at 28.5x zoom but basic 1mrad scaling is same. Therefore two ZBR 0.25mrad lines equals one 0.5mrad hashmark step in Lapua application. Longer horizontal lines under ZBR center cross are with 1mrad vertical steps, as are wider main hashmarks in Lapua application too. 506m/556yd correct aiming point with ZBR is then right under fourth wide line, on next 4.25mrad hashmark. By checking mobile application trajectory chart, exact drop was 4.21mrad. With Zeiss reticle nearest 4.25mrad hashmark, difference was 0.04mrad which leaves 20mm/0.79" error. Remaining difference was less than one 0.25MOA click, which is 36mm/1.42" in same distance. May sound complicated, but is actually not: set distance, aim accordingly, shoot, hit. Theoretical 4.21mrad vs 4.25mrad error at 506m by the way is equal to finger thickness. Application is also showing aiming point slightly left from target center, even with wind magnitude set to zero. This is to compensate bullet drift caused by bullet spinning. Spindrift is always to same direction with rifle barrel rifling, almost always right. Tested Scenar with 804mps/2638fps muzzle velocity from 11" rifling spins 172670rpm, and this causes gyroscopic force strong enough to slightly shift bullet in horizontal plane. To compensate right drift, aiming point must be left just as applications shows it relatively to target.

 

 


While writing this article and just after shooting, Zeiss published their new mobile application.  I tried with this new app and also benchmarked it against Lapua's mighty 6DOF mobile ballistic engine. Zeiss application uses traditional G1 drag function for calculations. It is not as precise as later G7 function, Cd/radar based calculations or highest precision 6DOF calculations, but gets the job well done for almost any hunter. Just to be sure, I calculated solution with identical weapon and environmental inputs we used for 506m target. Difference against 6DOF engine was 0.12mrad or 6cm/2.4" lower impact point, so very close to high-end calculator. To put it in perspective, even reasonably accurate rifle shoots about 15cm/6" groups to same distance, so theoretical error is 40% of practical vertical POI deviation. G1 calculator error stays in this ballpark up to 700...800m against best ballistic engines, depending about caliber and bullet. So it is rather safe to assume that it is precise enough for any hunter. Zeiss ballistic engine does not calculate spin drift, as most of similar free applications. Application can fetch temperature, relative humidity and air pressure from nearest station automatically so environmental variables are taken into account conveniently, weather updates by simply pressing blue thermometer symbol. Also shot angle can be compensated for precise hits, when in mountains for instance.

Most interesting part to hunters is that Zeiss application takes advantage of explained zoom vs reticle scale change phenomenon- it shows reticle-scaling practical results in fly. Whichever zoom is set to input field, app shows exactly on which distance reticle hashmarks will match relatively to actual bullet trajectory. This is interesting and very beneficial feature as shooter can easily check best zoom for hes own ammunition and muzzle velocity. For instance, I was able to find very sensible reticle scaling under minute for Sako A7 with used Lapua 167gr Scenar: on 27.4x, hashmarks match almost perfectly to 200-250-300-350-400-450m range true drops. Very handy! Also if ammo or weather changes, re-calibration can simply be done by checking app and fine-tuning zoom again. Application shows drop and wind deflection in table chart as well. Inches, centimeters, MOA:s and even mrads (mils) are covered so it is direct turret adjustment compatible too. Horizontal aiming point for wind is not shown in reticle pic, so it will have to be adjusted from turret anyway. "POI" button as on capture does not have functionality, so this might suggest that update with windage aiming poit migh be coming soon. Or not.

 

 

 

506m/553yd plate check. Five shots in 13cm/5.1" group. Nice 0.88MOA result. Especially with fist support and shot at barely visible shape in white mist. Fists were numb because of wet gloves, probably offering some unintentional stabilization. It was still rather clear that weather (and shooters) limited rifles true potential. Hits were clearly opened more vertically than horizontally, probably because lower edge of plate was impossible to see in fog. Impacts were also low because Zeiss magnification was not checked (= hurry, rain, cold fingers + usual excuses). Shooting was done with little over 29x magnification, larger than mrad calibration 28.5x is. Additional magnification shrinks reticle, so we did not use enough elevation in spite of aiming with correct point of reticle. Photo includes also some poor-man's photoshopping. One individual impact is hidden behind finger, in right edge of target. It was shot that was taken with scope phone adapter, aimed hair away from impossible to see from mobile screen. Rifle could not be held against shoulder, butt was semi-losely against bicep. Head was back and 90deg angle to see even something from screen, so position resembled more spastic chimp than seasoned operator. So, with your permission, we would like to think it positively: Against all odds we were still able to hit it.

 

 

In beginning of video foggy target is next to center cross, right and up. As soon as target was found, aiming point is raised up, to 4.25mrad short hashmark. Hesitation follows, reticle was moved away to left because target was temporarily lost inside hairline jungle. Mobile screen too close to eye added affliction even more, final shooting position would have made even most flexible ape jealous. Rifle recoils without control and target is lost from screen. Still a hit, high and right but still. Besides, believable excuses are sign of experienced rifleman. Video also showing strange swirl-shaped distortion on image. This reflection from lens, scope did not actually have such.


 

To intermediate 631m/690yd range only one shot was taken, hit with first shot. Horizontally on dead-center, but on lower quarter of plate. Also this distance we had accidentally too much magnification and too small reticle scaling -> not enough elevation. Video was taken trough Zeiss Diascope 85 spotter, true magnification in video +100x. Targets were visible better with big spotter. At this point, aiming with riflescope was close to impossible and mist got even denser for last 721m/788yd distance.

Bullet flight time to target 1.08s, impact sound return 1.95s. This clip wont probably win any special effect nominations, but at least it has sound. We hauled spotter + tripod to woods, so it must be published too. Shot and impact audio captured, rest is up to imagination, unfortunately.

 

 

Next and last distance, 721m/788yd was more challenging and not only because of fog: Elevation for this range with 804mps/2368fps MV, 4C/39.2F temp, 1010hPa/29.83inHg pressure and with 100% RH was needed almost exactly 8mrad- 7.98. When ZBR reticle center-cross is zeroed at 100m and reticle is scaled to mrads (28.5x), maximum aimable hold-over elevation is 5.5mrad. (fifth wide line + 2 hashmarks under it). So we were 2.5mrad short. Luckily enough, Zeiss has ASV turret and it had enough free travel up. Small trick solved situation: Reticle distance up from center, 2.5mrad, converted to MOA is close to 8.5MOA: 1mrad = 3.438MOA, 1MOA = 0.291mrad. So 34 clicks of turret adjustment will shift 100m zero very close to this highest point of vertical hairline. Aiming point was then taken relatively to this new zero point- 2.5mrads of upper part of hairline + 5.5mrad lower part of hairline = 8mrad total. Turret set 8.5MOA up, aiming to lowest part of reticle, two rapid shots and 2 hits. During this shot preparations also incorrect zoom (used in previous ranges) was noticed, so shots were taken with correctly scaled mrad reticle on 28.5x. Fog also intensified during preparations of these two shots, so unfortunately they were  last ones we took.

 

 

 

 

 

 

Conclusion

Operating outdoors in cold and rain makes one appreciate basic things. Things that simply work.

Zeiss turrets can be operated with thick gloves on. Reticle with SPF scaling open interesting possibilities for advanced hunters, but will work equally well with those who know only basics. Zeiss mobile application helps a lot, and actually make it easy. Zeiss image quality is good. As expected from scope made in Germany. Fluoride- or "FL" -lenses are still highly valued by birdwatchers too for a good reason. Despite of German birth, this Zeiss is MOA- based but can still be efficient and reliable for any "metric" user in Europe. Only thing needed is very basic knowledge of principles- and Zeiss application takes care of rest.

At least as positive surprise was Sako A7 Roughtech Pro. I have used to heavy precision rifles, but Sako showed that even wildest stories in internet may actually be true. I could take this individual rifle to any long-range field shooting event. I would also have no problem to lay it down to same row with +4000€ precision rifles, with straight face. Rifle seem to fit perfectly for those hunters who appreciate sturdiness and repeatable accuracy in same light package. I would imagine it also suits well for laborious mountain carry, or for basic moose hunter who wants general purpose rifle capable for birding too- in any conditions. Chain is still always as weak as its weakest link. Rifle shooting this well can still not do it without quality ammunition. Lapua's factory load worked straight away, better than well. Weather with visibility problems + shooter limited this package true potential, at least some amount.


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