Comparison of All Test Optics: Final Analysis

This will be the final article in my series of articles documenting my comparative testing of the U.S. Optics SR-8c 1-8×27, the Swarovski Z6i 1-6×24, the U.S. Optics SR-4c 1-4×22, and the SWFA SS HD 1-6×24.  I also had an Aimpoint T1 Micro on hand to compare with these scopes.  I would like to extend thanks again to my friend at U.S. Optics for loaning me the Swaro, Aimpoint, as well as the two U.S. Optics scopes and to Ilya for loaning me the SWFA.  Without their kindness I would not have had this opportunity, which for me was a lot more than just being able to play with expensive stuff; it afforded me a chance to gain valuable insight a significant piece of how the visual process works in shooting an AR though the spectrum of speeds and distances that it’s commonly utilized in.

Something I really haven’t explained fully is what I expected from the rifle system that I was testing the optics on.  Part of the reason for that is I did not really have a very concrete idea of what I did expect coming into the tests.  I think I have a better handle on that now.

My concept for this AR, which I’m calling the X-15 (also a cool rocket plane) during its run as an experimental platform, is to be a versatile rifle that will allow me to excel in the “very close to the close end of mid-range” distances, which I’ll define as room distance to 250 yards.  My vision for such a rifle was that it would have a barrel capable of shooting sub-MOA “all day long” (sarcasm), have a sighting system with sufficient magnification to locate, ID, and engage targets out to the maximum system distance as a precision rifle system within that range.  At the very close end, I wanted the system’s scope to have the capability for no magnification and wide field of view for rapid hits.

My vision for using such a system is that it would be zeroed at a particular distance, and holdovers utilized to adjust for targets outside of the point blank range for the target and trajectory.  Since I’m working with a ~4.2” target, in my estimation the danger space (portion of the trajectory in which the bullet will strike a target of a given size) is that it’s sufficiently narrow when taking into account a realistic amount of shot dispersion to rule out any of the “battle sight zeros”.  To that end I used a 100 yard zero.

Part of figuring out what is important to me in an optic for a rifle of this type is to weigh which performance attributes are most important.  I don’t think the optic that is the best of all worlds has been made yet, so there’s going to be a tradeoff in making a choice.  I don’t think there’s a way to make a generic matrix of how to perfectly weigh the tradeoffs for everyone, because individual requirements, situations, terrain, and targets vary.  About all I can do is look at my terrain and expectations of the rifle.

Close Range:

Initially I had been dismissive about the necessity of what I think of as a non-magnified low end (I don’t believe this is a technically correct description of how the optic works, but it is descriptive of how it’s used).   I had figured that at the closer distances in which speed is paramount, some non-sighted method of aiming would be sufficiently accurate.  That would be the only method that I know of that would be as fast or faster than using a 1x (or non-magnified) optic.  That belief was based on my recollection of results in point shooting a year or so back.

For the size target I used in these tests, in some recent testing I was not able to get a high enough hit rate without using sights to satisfy my own requirements with the 4” target at 7 yards.  I didn’t test any scopes in this comparison that did not have a 1x capability, so I can’t speak to how much time would be added by magnification, but I would guess that it is going to slow things down to some degree.  I therefore came to accept that if I require the rifle to perform to my capabilities at close range I want it to have “true 1 power”.

Based on what I experienced during my testing there were a few things about certain scopes that I appreciated for certain facets of performance.  Think of these as my requirements for the perfect scope in terms of close range shooting.

-Non-magnified “unity” image (same size as what the naked eye sees)
-Generous eyebox
-Uncluttered reticle
-Minimally obstructive visual profile
-A simple “daylight bright” red dot aiming point
-Lack of downrange signature in the illumination (not visible from the “business end”)

There were also things that I felt detracted from my shooting at close range.  Here is a brief list of things I don’t want up close:

-Significantly obstructive scope visual profile
-Tight eyebox
-Compex reticle (abundance of ‘features’)

I had no preference for first or second focal plane reticles up close.  Just give me a bright dot I can see.

A bright, clear image and large field of view are pleasing attributes to have in a scope.  When you put the big money down and bring the scope for your friends to marvel at, those are the things that generate a lot of oohs and ahhs, and therefore a sense of satisfaction.  In my testing those attributes did not play out to increased speed.  Neither the Aimpoint T1 nor the U.S. Optics SR-4c have especially bright images.  In terms of image quality, while the SR-4c has good clarity to my eye, the T1 is not at all impressive.  Both of these optics were, however, very quick.

What did seem to be the case with the optics that stood out to me for the brightness and clarity of their image was that I shot a little slower with them, but that my hit rates were higher.  These were the SWFA and the Z6i.

My knee jerk reaction in the word association game is that upon hearing the words “close range” I immediately answer with “speed”.  After some thought on the matter I decided that although proximity would seem to have a direct relationship with imminence, it doesn’t have any inherent bearing on the necessity to sacrifice accuracy for speed.  Close range carries no built in excuse for a substandard shot, although I would guess that is typically the case, close things appearing larger than far things (duh).  I can envision that in certain circumstances, depending on what else was near the target, it would be necessary to take all the time necessary to make an accurate shot, albeit in a hurry.   That is why we practice.

In any event, I decided that for my needs I have to favor the hit rate over the greazy lightnin’ fast speed.  I think that any of the scopes I tested could be used to good effect to satisfy those requirements with some practice.  While I believe the performance differences I saw were real, they were relatively minor.  I just think that some do it more readily and ‘willingly’ than others, those being the aforementioned SWFA and Z6i.  Of those, the Z6i is significantly easier to shoot with.

The “low margin” distances (25-100)

It’s hard to know how to categorize things sometimes because a person’s perspective can drastically affect how they view it.  I could call the 25-100 yard distance piece of the distance spectrum a lot of things, but in shooting it recently I felt as if it provided the lowest margin for error given the requirements I faced.  I discovered that this is a difficult range when the target is relatively small.  This was the portion of the distance spectrum that the DD25 drill (Test #3) would have gotten at if I had been up to it.  The problem with a small target in this distance spectrum is that the close proximity to the target still strongly conveys a rather urgent need for speed (cue: Top Gun high five/low five), but the target size requires care with one’s marksmanship.  My personal discovery was that the combination of requirements for speed and relative precision make this type of shooting very demanding in a way that is unique.

There wasn’t a lot that I felt like I really needed from my scope at this distance other than a bit of magnification and a reticle I could see.  I still needed about an inch and a half of holdover at 25 yards to compensate for mechanical offset, so it was helpful to be able to see the target with clarity under magnification.  The non-magnified Aimpoint T1 was a liability in this stage of testing.  As always, a generous eyebox is appreciated.

Again, I had no real preference either way for a reticle in the first or second focal plane at this distance spectrum.  I could see either one without issue.  The rationale for a first focal plane scope is the necessity to have the reticle scale be valid at all magnifications.  As far as holdovers go, any hold inside of 100 yards would be done to compensate for mechanical offset, and I would not use a reticle scale to accomplish that.  It just over-complicates something that can be accomplished with small amount of familiarization fire.  A wind hold at those distances would require extreme weather conditions that, while possible, are not likely enough to factor into features I’m going to demand from a scope.

I could see that the argument could be made for a first focal plane reticle being useful to engage a moving target in that distance spectrum.  Within those ranges there is also an argument for techniques that have nothing to do with using a reticle.  I could also make the point that 6x or even 8x for movers at that range is not an impossible mission if you really wanted to use a second focal plane mil scale and just had to turn up the scope to max power.   I’m going to withhold judgment on the subject of movers until I really try to refine my ability to engage them.

“Generic” Precision- 100 yards

I consider 100 yards to be in the “neither close nor far” category.  This was the point that I definitely felt a preference for a second focal plane reticle in terms of obtaining a precise sight picture.  As far as power was concerned, I felt that 4 power felt like it put me at a rather significant disadvantage as far as precision, but that actual disadvantage was rather minor.  The more significant disadvantage with the 4 power SR-4c was in ease and speed of use, which put the average split time with that scope almost a full second per shot behind the Z6i.  In contrast, at 100 yards 8 power didn’t seem to have any advantage over 6 power.  So for this type of shooting I’ll say that the following attributes were preferred:

-Second focal plane reticle
-≥ 6 power

At longer Ranges

While I think there is an argument to be made that in every other test of shooting the differences in scopes were relatively minor, when it came to using the scopes to hit a small target beyond the system’s point blank range, there were significant differences that could have a decisive effect in the outcome of one’s efforts to actually utilize the rifle system.  In the end I think that the total points for the long range tests gave the best indication of performance.  The U.S. Optics SR-8c and the Swarovski Z6i were both way ahead of the others.  I can say with certainty that the extra magnification of the SR-8c did help at the 270 and 330 yard markers, but before that it did not seem to be a factor.

The things that made the optics excel in the final test were:

Power: ≥ 6 power good, ≥ 8 power better
Usable reticle scale at all ranges (including inside 200 yards).
Detail and complexity in the reticle seemed to help beyond 250 yards.

The Total Experience:

If I combined the attributes I listed for each piece of the required distance spectrum of the rifle system it would read about like this:

-Maximum power ≥ 6 power good, ≥ 8 power better
-Non-magnified “unity” image, i.e. “true 1 power”
-Generous eyebox
-Uncluttered reticle, but…
     …with more detail in the scale below the 0.5 mil mark.
-Minimally obstructive visual profile for the scope overall, i.e. high image to overall visual
     signature ratio
-A simple “daylight bright” red dot aiming point illumination
-Lack of downrange signature in the illumination (not visible from the “business end”)
-Tube and saddle configured to allow for flexibility in mounting options
-Turret adjustment increments ≤ 0.1 mils, as a good zero is kind of important.
-Clear, bright glass
-Second focal plane reticle preferred

What I Would Buy:

First of all, I need to point out that I didn’t spend all that long with any of the optics.  That was kind of the point- to see how easily they meshed with me without much opportunity for me to adapt to their idiosyncrasies.  I got a good idea of what features seem to be inherently superior for different applications, all other things being equal.  The thing to remember is that we use practice to ensure that all other things aren’t equal in order to gain strategic and tactical advantage.  I think that some of the nitpicky points I made, such as the visual complexity of the SWFA reticle, and the liability of the relatively low power of the SR-4c, could be overcome with some more intensive practice.

I also felt that I needed to be especially frank in my evaluations.  To that end, if something had even a slight tendency to annoy me, I made no attempt to get over my annoyance.  On the contrary, I tended to dwell on my dissatisfaction.  That completely contrary to my normal tendency when using my own gear.

I also tried to control any enthusiasm I had for any of the scopes that I seemed to naturally gravitate toward, like the SR-8c and the Z6i.  Sometimes feelings and impressions can be misleading.  My goal was to let the test results do my deciding.

If money were no object:

Objectively I would have to say that the SR-8c was the most solid performer across the spectrum of shooting that I did.  I’ve already written a lot about it specifically, but just to recap, although it’s heavy, it’s all business.  Nothing about it is superfluous.  It works.  The reticle is simple and effective.  The illumination is, all in all, about the best I have seen (I give it extra points for the lack of downrange signature), although I preferred the control module of the Z6i.  I have also been told that the drawback of that style of illumination is the slightly darker image, which did not bother me.  The only things I would change on it would be finer adjustment knobs and more mounting room on the tube on the front end.  This would free up some mounting possibilities, which would be very welcome.  I would also prefer a second focal plane version with a simpler reticle (I drew one and gave it to my friend at USO), but not so much as to sway me.

Subjectively I absolutely loved the Swarovski Z6i.  In the tests I felt that the Z6i kept up with the SR-8c up to the 230 yard mark, where the extra power of the SR-8c gave it a definite edge.  The BRT-I reticle is almost perfect.  I believe that second focal plane is the way to go in this application.  The eyebox is very forgiving.  The illumination is nice to the eye and the control module is very well thought out, but it does have a downrange signature which does bug me a little.  I would prefer 0.1 mil knobs (or finer) to the 0.15 mil knobs it has.

If my shooting were likely to be limited to shorter distances or included larger targets I would also seriously consider the SR-4c.  In my opinion it beats the Aimpoint at its own game up close and leaves it in the dust as the range increases.

Choosing in the real world:

I’m torn.  I am considering selling some rifles to better outfit the X15 (and change out the X designation eventually).  It’s such a handy and usable platform that it makes more sense to make it all it should be when I have guns that I don’t use much and only still have because they are kind of cool.  What makes it difficult is that it’s hard to cross the emotional barrier of selling something like an M1A and still not having enough cash to buy one of the scopes that I think would be best.  $2500 is a lot of money for someone with a family to spend on anything that won’t pay the bills or provide a shared benefit for everybody.

The ~$1000 price tag of the SWFA is reasonable to me.  There was nothing substandard about the build quality or anything like that to rule it out.  The quality of its image really was almost up there with the Z6i.  There are a lot of people out there with no negative comments at all with reference to that scope.  The fundamentals of that scope are nicely done and solid.  I just didn’t like the reticle for the application and the illumination is not up to what the others provide.  There are so many scopes that I haven’t tried that I’m not ready to lay my money down on the SWFA.

The Vortex Gen 2 Razor 1-6 looks like it has a very nice set of attributes.  Sightron has an interesting 1-7.  Ilya is testing out a Meopta 1-6×24.  There are other possibilities.

For the time being the rifle is bare of any sighting system, so it will be going on the shelf for a while.

Comparison of All Test Optics: Test 5- Long Range Transitions

I apologize again for the lack of frequency in my posting lately.  I still have a lot going on, and a moderately high constant level of stress, which has put the tasks of writing and making charts lower on the priority list.  As always, when you notice that things seem to be back to ‘normal’, they probably will be.

Links to Individual Optic Test Results:

U.S. Optics SR-8c
Swarovski Z6i
U.S. Optics SR-4c
SWFA SS HD 1-6×24

The intent of this final test was to take 4 shooting systems, manifested by the same rifle wearing 4 different scopes, to the commonly accepted limit of effectiveness of the 5.56 NATO cartridge, and determine the ease and accuracy that the systems (scopes) could be utilized to engage targets at distance.  I should mention that I understand that there are good reasons to re-think the conventional wisdom on maximum distance of effectiveness of that cartridge, depending on application.  In my case, the context of my shooting has been within the confines of the goal that I have set, which involves a 4” target within 200 yards. This test exceeded that distance, so this test viewed in that context can be classified as “long range”.

New Target

The idea of the test was to evaluate the scopes in terms of how well I could see targets at longer distances, how effectively I could use the reticles to hold over, and how easy it was to do those things.  I tried to eliminate any variables that did not address those things.  To that end, I shot from bipod prone with a rear bag and began in the shooting position with the rifle loaded, a round chambered, a spare mag within easy reach, my holdovers written down, and me wearing a diaper to eliminate the possibility of distraction for the 6 minute or so duration of the course of fire (and my new nickname is “Pampers”).

The target distances were 170, 230, 270, and 330, within a couple yards margin of error.  The targets were arrayed in a different order, left to right, for every test.  9 shots were fired at each target, for a total of 36 rounds for each optic.  The sequence of engagement, left to right, was optimized to balance the permutations of transitions from each target to each target, and this sequence was maintained for each optic.  In other words, the physical order of targets changed while the shooting order left to right was maintained.

The targets were placed between a relatively narrow corridor, defined by a vehicle gate between a large field and a pasture, the gate being approximately 100 yards downrange.  All of the targets were visible within a single sight picture, as my goal was not to test my ability to physically transition, but simply to align the sights on a new target with an appropriate hold and fire as quickly as possible.  Actually, for each shot I needed to check the sequence number, verify holdover, acquire sight picture, press trigger, grab my pen, mark the shot on my sequence list, and repeat.  The magnification for each scope was set at the maximum possible for the given scope.

IMG_6152

IMG_6005

The size of the ~4.188” targets in MOA at each distance, closest to farthest, was 2.35, 1.74, 1.48, and 1.21 (avg: 1.695 primary target diameter, radius: 0.8475).  Note that the mean radius from the previous test over the course of 30 rounds per optic, in MOA, was between 0.834 and 0.968 (mean diameter up to 1.936 MOA, which means of course that some of the rounds were outside that diameter).  That means that the dispersion of the average shot would put it outside the target at the 230 yard mark for all of the optics except the Z6i, even with an absolutely perfect zero (a rarity).

I have had samples of some ammunition shoot from this rifle with a mean radius in the 0.3ish range, so it could have been possible to increase my odds of success with better ammo, but as I noted previously, I only had sufficient quantities of XM193 on hand for testing.  Would a finer comparison have been possible with better ammo?  Probably, but I only have what I have.

My zeroes were fine tuned using the data from the previous test, which measured only precision (group location was irrelevant).  I measured the deviation of the center of a 30 round shot group from the center of the target using On Target TDS and corrected accordingly.  During that step I was wishing for finer adjustment increments in all the scopes with the exception of the SWFA, which has 0.1 mil adjustments.  I would prefer even finer adjustments to get my zero just right.  Instead, the scope makers are providing the scopes with coarser adjustments for the folks who like to dial and want to do it quickly.  Or is it that they see the AR as a coarse instrument?  I’m not sure, but for this application I would only touch my knobs for zeroing, and to my way of thinking, let me get the best zero I can.  On the SR-4c, which has 0.2 mil adjustments, I went so far as to program the zero offset into my ballistic computer, because I just wasn’t happy with how close to center I could (couldn’t) get.

Each rifle system (as designated by the scope the X15 was wearing) was evaluated for accuracy, precision, with the measurement of speed noted to get at the element of ease.  Accuracy was expressed by the deviation of the group center from the target center, as expressed in MOA.  Precision was expressed as mean radius, also in MOA.  Points on the target were measured, and serve as a combined measure of accuracy and precision.  Speed will be expressed as an average split time.

After graphing the results I found that although the precision and deviation results were interesting, they don’t mean much separately.  The points are much better in that it gives a total measure.  I also will add a montage of each target at each distance and make a note of which scope is subjectively most intimidating as the one I’d like least to be shot at with.  Take the last one how you will.  There is often a fine line between brilliant and stupid.

170 yards.  Target Size (5 point hit zone): 4.188”/2.35 MOA (radius = 1.175 MOA)

This target seemed pretty close subjectively.  My holdover was only 0.1 mils.  At this distance the precision for the scopes that I have good data for doesn’t show that significant a difference.  The SR-8c was the most precise, but even with a perfect zero would not have been good enough to keep all the hits inside the ~4.2” target.

Test 5 Graph Precision at 170

I’ll explain the format of the above graph, although I think it’s probably obvious.  The wide bars illustrate mean radius.  The narrow bars illustrate extreme spread.  The target’s dimensions are illustrated on the right for comparison.  All the values are in MOA.

The deviation showed that both the SR-8c and Z6i were very close to the point of aim, both well within the correctable amount of their turrets’ adjustment value.  The SWFA had considerably more deviation.  I look to the scopes’ reticles as the primary attribute that affected this measure of performance.  Note that the SWFA scope has a floating dot in the open center of the crosshairs (that don’t cross).  I think this may have made the rather small holdovers at the closer ranges less precise in terms of deviation.

Test 5 Dispersion Graph 170

The format of the deviation graph should be obvious, but also note that the scale matches the graph measuring precision above it (despite the difference in the frame size), so when they are both viewed together you could get some idea of what the group size was and how far off it was.  Or just look at the targets, which follow.

The points showed that while the SR-8c and Z6i pretty much stayed together closely, the SWFA really fell off the chart.  When you combine the worst precision with a considerable amount of deviation, the results really show in the points.

Test 5 Points 170

The actual targets are below.  The first array is different than the rest in that they are out of the order I tested them, because the SR-4c was not a valid group due to some of the hits being off paper and not accountable.  In the following photo the targets, left to right correspond with the following optics: SR-8c, Z6i, SWFA, and SR-4c.

170

For the “poking the head up out of cover” measurement, I count the SR-8c as the most intimidating, and the Z6i a close second. After that I rate the SWFA over the SR-4c.

230 yards.  Target Size (5 point hit zone): 4.188”/1.74 MOA (radius = 0.87 MOA)

This distance was really the last point of comfort for the magnification level of all the scopes except for the Sr-8c.  My hold at this distance was about 0.4 mils.  It may have been 0.5 for the scopes that I used the lower Nightforce mount on, but I can’t remember for sure.  For whatever reason, this distance was the Z6i’s opportunity to shine.  This was the closest that any of the scopes came to having a group extreme spread that would fit inside the target.

Test 5 Graph Precision at 230

Of course fitting the group in also depends heavily on how well centered it was.  One constant with the Z6i was that its deviation from the target center was never more than 0.11 MOA, and in this case was 0.07 MOA!

Test 5 Dispersion Graph 230

This, predictably played out well in terms of points for the Z6i.  I can’t say that it exactly dominated, because the SR-8c was close behind, both of them well ahead of the rest.

Test 5 Points 230

The targets from here on out will be, left to right, SR-8c, Z6i, SR-4c, and SWFA.

230

I would say that I find them from most intimidating to least, the Z6i, SR-8c, SWFA, and SR-4c, which in this case mirrors the point rankings.

270 yards.  Target Size (5 point hit zone): 4.188”/1.48 MOA (radius = 0.74 MOA)

Something interesting began to happen at this distance.  Note that all these were shot in a randomized “round robin” sequence, so it’s not really accurate to say that it “began to happen at this distance”, it just feels natural to say it that way.  Anyway, the interesting thing was that the SWFA scope began to perform better and the Z6i started dropping off a bit.  These are both 6 power scopes, so I find that interesting.  I think the main difference is the complexity of the reticles- the SWFA is quite complex while the Z6i is quite simple.  The SWFA also has an open center with a fine dot for aiming, which of course I wouldn’t have been using at these distance due to the holdover required.  I think that the reason the SWFA started improving was that the holdovers at this range were well clear of the open centered portion of the reticle.  Also note that the Z6i dominated throughout in terms of deviation of group center from target center, but tended to be worse as far as precision.  The limited power of the SR-4c was also a huge liability at these distance with such a small target.

Test 5 Graph Precision at 270

Test 5 Dispersion Graph 270

Test 5 Points 270

270

Oddly, I find the Z6i target to be most intimidating.  I’m basically looking at hit rate here, probably for the obvious reasons.  A hit rate graph would be nice wouldn’t it, but I’m sick of making graphs for the time being.

330 yards.  Target Size (5 point hit zone): 4.188”/1.21 MOA (radius = 0.605 MOA)

The extra magnification of the SR-8c allowed it to dominate at this distance.  The Z6i showed an incredibly low amount of deviation from target center to group center, sufficient to score it a decent amount of points, even with its less than stellar precision.  The SWFA seemed to do fine while the SR-4c was just out of its element, not due to group size but due to deviation.

Test 5 Graph Precision at 330

Test 5 Dispersion Graph 330

Test 5 Points 330

330

Total Performance:

When taken as an average, the precision varied little between the systems, with the SR-4c lagging just a bit.  What made the scopes perform better in general was the balance of low group deviation and precision.  If the Z6i would have shot a bit tighter it would have ruled the entire thing, but the SR-8c just did a little bit better job of balancing everything.

Test 5 Graph avg precision

The SWFA suffered by its relatively larger deviation, especially at the closer ranges.  The fact that it performed comparatively better at longer distances indicates to me that the reticle is optimized for longer distances, which makes sense given its complexity.  What is puzzling about that scope in my opinion is that with a 6 power maximum magnification it will never be optimized as a long distance optic, which, coupled with that reticle makes the scope something of an oddity.

Test 5 Dispersion Graph AVG

The SR-4c, while a superb scope inside 100 yards, seemed to be simply outside its element.  I should note again that the target I used is small for most uses, and that a person could probably double the distances for most applications.

Test 5 Points Total

Finally, I included the average split times of each optic to indicate ease of use.  There really isn’t much difference.  Note that the SR-4c wasn’t difficult to use for this test.  It was actually easy because I just had to accept what I had, just like with irons.  It just didn’t work as well as the scopes with adequate magnification for the task, as exemplified by the SR-8c.  There must have been something about a 6 power scope, because they were the same down to the hundredth of a second.

Average Split Time

If price were no object, I think that the obvious choice for rapid transitions at what most people would consider mid-range distances is the U.S. Optics SR-8c.  It wasn’t always the best at each distance, but it was pretty consistently in the top (or close enough to still hang in there), and consistent enough across the board to score the most points.  While I find the Z6i compelling for its amazing image and field of view, the simplicity of its reticle and because the second focal plane makes a lot of sense to me, it just seemed to lose its luster past the 230 yard mark for some reason.

I’ll sum up my thoughts of the performance of the optics as a whole in the next, and last article in this series.  Thanks for reading.

Comparison of All Test Optics: Test 4- Precision at 100

First of all, I apologize for my sparse posting lately.  I have some intensive life type business that is taking up my time, resources and mental energy.  This will probably continue until you happen to notice me posting more often.

Links to Individual Optic Test Results:

U.S. Optics SR-8c
Swarovski Z6i
U.S. Optics SR-4c
SWFA SS HD 1-6×24

This was a straightforward test.  The main idea was to test the precision of the shots with the scopes.  Secondary to that I wanted to use time as a measure for the ease of use of acquiring the sight picture, not only for each shot, but also when taking a position.  I started in standing with the bipod in the ready position and got into bipod prone at the timer signal.  Each shot was taken on a separate bull’s eye, and they were compiled into groups using On Target TDS.  I shot three strings on 10 shots for each scope.  I compiled the shots into 10 shot groups for each string and then finally into a total group of 30 shots for each scope.

The ammo for every test was Federal XM193, lot number v 55 Z531.  I would rather have used something that would offer better precision, but I only had the ball ammo in sufficient quantities for the testing.  I believe that if nothing else the ammo is consistent, which is really all I need to make a comparison.  The condition of the barrel for each testing run was comparable, as I cleaned it at the outset of the battery of tests for each optic.

I didn’t bother to conduct this test with the Aimpoint or to retest the SR-8c.  I could tell the Aimpoint was already out of the league of the magnified optics at 25 yards in the previous test.  With a bipod and rear bag I didn’t see the results of the SR-8c changing appreciably.  Also, I have a finite supply of time and ammo in this life, and I had to decide that neither was best allocated to test the obvious.

I considered showing the results in a variety of formats.  I had 3 ten round groups for each scope, for a total of 12 groups.  I looked at the results as a collection of individual groups from best to worst.  I looked at the average of the 10 round groups for each scope.  I finally decided that nothing really added to the total 30 round composite groups for each scope.  Here are those:

SR-8c:

TgtGfx2108

Z6i:

Swaro 30 Shot

SR-4c:

30 Rounds
SWFA

30 Round Group

I apologize that the size of the photo depends on how I cropped it at the time of the origial article, and that varied by how large the group was.  To make the results easier to digest, here are some pertinent numbers for the 30 rounds groups  They are listed in order from best to worst according to mean radius size:

Test 4 30 Rounds

I see the mean radius as the easiest number here to look at to get an idea of how the system performs.  It’s an apples to apples number, regardless of whether some scopes had wild ‘outliers’ and others didn’t.  Using mean radius as my standard measuring system allowed me to maintain some sanity and perspective when looking at performance.  There isn’t much guessing, and the number is pretty much what it says it is.

I still included the extreme spread of the groups.  Although it might not be as useful a statistical tool, as a shooter I still appreciate seeing a worst case scenario.  Also, a 3 round group extreme spread is worthless, but a 30 round group will tell you something.

In terms of time measurement, I think the average split time will tell you the most about the ease of use for the scope.  Establishing the position got quicker and quicker as I went, so the first shot time pretty much only tells you that in numbers.  Since I had to locate a new bull’s eye for each shot the split times are a better measure of how easy it was for me, and since the number is an average of 27 shots (30 minus the 3 first shots) of me doing something that comes pretty easily, naturally, and without thought, I don’t see much room for wild deviation, as in the previous test.  I listed the results in the order I used the optics.

Average Times

The clear, bright image and second focal plane reticle of the Z6i made it really easy to use for shooting a group at 100 yards.  It just edged out the SR-8c in terms of group size in terms of mean radius while the SR-8c barely had a tighter extreme spread.  The extra magnification of the SR-8c made it nearly as easy to use, its disadvantage being the large first focal plane reticle obscuring more of the target than was optimal.

The bold and complex reticle of the SWFA made it difficult to find the target center.  The target was black on white paper and bracketed nearly perfectly within the open center of the SWFA, but the SWFA reticle is very dark black while the target was rather thin and about as dark as you’d expect a laser printer to print black ink.  The SR-4c, being 4x was difficult in comparison to the SR-8c and the Z6i only because it had less power.

As far as precision goes, all other things being equal, a second focal plane reticle will be an advantage.  The other obvious advantageous attribute, all other things being equal, is magnification.  The Z6i would be my choice for this type of shooting at this distance.  It would be nice to have a bit more magnification, but not necessary.

Comparison of All Test Optics: Test #3- Medium Range Positional Shooting

This test attempted to measure the friendliness of the scopes to multiple positions under a serious time crunch.  The target was the standard target I’ve been using, a ~4.2” target, placed at 25 yards.  The drill is as follows: Begin with a magazine of 5 rounds.  5 shots standing, reload with a magazine of 10 rounds.  Shoot five rounds from kneeling, shoot five rounds from prone.  A passing score requires all hits in 15 seconds or less.

Hits were measured as hits in the 5 zone, which is the primary target on the paper.  A hit is defined as more than half the bullet hole being in the scoring ring.  The target is printed on an 8.5” x 11” sheet of printer paper.  Here is the target:

New Target

I spoke on accuracy and reliability of test results in the last post.  This test turned out to be essentially invalid.  I don’t believe that the problem was in the accuracy of the testing methodology.  I think the test has the potential to measure what I intended to measure.

I believe that the problem is that my consistency of skill in solving this shooting problem was way too erratic.  We all know that equipment is basically secondary to skill, within reason.  Equipment does make a difference, especially when there is a great disparity between one item and the next.  When the equipment is basically comparable in class, the differences will be fine.  If the shooter’s consistency isn’t well within that margin, it won’t be possible to see how the equipment affected the differences in performance.  That’s what happened here.

Here’s what I can say about what happened over the course of the testing:

I got faster.  That is good.

Test 3 Average Time

My hit rate went rather steadily down.  That is bad:

Test 3 Hit Rate

In the balance of speed and accuracy, my performance over time degraded.  That is bad:

Test 3 Raw Points Per Second

I was not great in the extreme close range type of shooting, but I was at least consistent enough to make a comparison.  Tests 4 and 5, in the 100-400 yard venue, worked toward my strengths.  This test was in a style in between the others.  The subconscious lesson that ‘worked’ for me in test #2 also affected my shooting in this test, but the context was so different as to have a drastically different result.  What saves your life on Sunday will get you killed on Monday.

In order to get better at this test I would first make an analysis of my gunhandling that was wasting time via video. Then I would reduce the distance (increasing the target size) until my hit rate would be 100% at the par time.  Then I would gradually extend the distance.  The idea is to begin where I actually am and steadily improve, pushing the edge of my envelope.

That is all.  Thanks for reading.

 

Comparison of All Test Optics: Test #2- Close Range Transitions

Links to Individual Optic Test Results:

U.S. Optics SR-8c
Swarovski Z6i
U.S. Optics SR-4c
SWFA SS HD 1-6×24

Thoughts on the Drill Itself

I’ve come to refer to this drill as the X-Box.  As I described before, this test uses directional transitions to test the friendliness of the optic to target acquisition.  Two target stands are placed approximately 7 yards apart.  Each target stand is 8′ tall and has a target at the bottom and a target near the top.  The shooter stands equidistant from each stand so that they are both approximately 10 yards from the shooter.

IMG_5790

Although the distance of this drill is not all that different from test #1, which is at 7 yards, the drill itself is qualitatively quite different.  While test #1 occurs over a very short duration, is a very simple shooting task, and puts 100% of the score into the outcome of 1 shot, the X-Box drill is more complex (I would call it ‘moderate’).  Test #2 occurs over a longer duration with more shots, which allows the shooter to leave the mental game of waiting on the timer, pre-planning, etc., thus reducing the mental game aspect of it.  Since the drill has more rounds it is less sensitive to mistakes, and provides a bigger picture of performance.

I would have liked to have the targets presented in a perfect square, but 21′ target stands are not realistic, and it was important to me to have a wide area between lateral targets to traverse.  I wanted the transition to be significant, and not simply a matter of picking up something that was already in my scope.  It is obvious that the up and down transitions were faster due to the much short distance between targets, approximately 6′ versus approximately 21′.  Shot #4, the first of the up/down transitions, was always the point in the drill when it felt like ‘it’ took over shooting for me and I just tried to stay out of the way.  The same phenomenon is probably what caused me to forget where I was going to in about 1 out of 4 runs.

Average Split Times:

Test 2 Average Split Times

What Makes an Optic do Better in This Drill?

I came into this drill expecting field of view to make a big difference.  Here are the published numbers for field of view at the lowest power setting of each optic from the manufacturer’s websites:

SR-8c                83.25′
Z6i                   127.5′
SR-4c              110′
SWFA              95′
I could not find a number for the Aimpoint.

I came out of the tests with a different theory, which I have already discussed a bit in the overview of the SWFA scope.  With an unmagnified optic, and shooting with both eyes open, field of view inside the scope is not exactly what is important.  The total field of view is what matters.  Essentially total field of view can be defined as everything in front of view minus what the rifle and non-see-through parts of the scope obstruct.  I initially expressed that as: vision = field of view inside the scope + field of view outside the scope – the field of view obstructed by the rifle and scope.  Note that the “-” symbol represents a subtraction sign and not a dash.  Since then I’ve learned something about reticles and have to conclude that the reticle, although necessary, is essentially obstructive in nature.  That would make it necessary to amend the formula to something like this: vision = (field of view inside the scope – that which is obstructed by the reticle) + field of view outside the scope – the field of view obstructed by the rifle and scope.

In light of my theory, and speaking of field of view, I should note that I did not shoot this course of fire with any of the variable power optics at the lowest power setting.  I have already noted several times that at the lowest power setting the image size appeared to be smaller than what I see with the naked eye.  Therefore the optics were “turned up” a bit, in each case somewhere between 1 and 2.  The SR-8c had to be turned up to about 1.6x, the SR-4c barely at all, and the two 1-6x scopes in between those extremes.

In terms of total field of view, I would rank them as follows, as viewed with a perfect sight picture, from best to worst: Z6i, SR-8c, SR-4c, T1, and SWFA.  I actually referred to through the scope photos to come up with that, although it is still based on my impression.  I was surprised to see that the SR-8c was actually better than the SR-4c in that respect, but the SR-4c had a thicker ‘flange’ of material between the in the scope image and the view outside of the scope.  What likely led to that confusion was performance in another key area: ease of eyebox acquisition.

The eyebox is the area that the eye needs to be in to see a perfect edge to edge image through the scope.  This varies quite a bit between optics and usually between powers of any single variable power optic.  This is probably an equally important quality in a scope to be able to transition quickly and accurately.

Ideally, the eye can discover a target, acquire it, and the rifle will be presented so that the scope image (via the eyebox) arrives at the eye, hopefully presenting an acceptable sight picture.  The tighter the eyebox, the more exacting that procedure must be, and therefore perhaps making it slower and more difficult.  The better trained the shooter is to acquire a consistent cheekweld, the less of an issue this will likely be, but no one is perfect all the time, and not all positions are as easy as others.  I cannot rate the eyeboxes of the test scopes objectively at this time, only from memory.  I would rate them as follows, from best to worst: T1, Z6i, SR-4c, SWFA, and SR-8c, with the last two being close to a tie.  None of them were bad at all, but the T1, being unmagnified, really didn’t have an ‘eyebox’ per se, and the Z6i is incredible.  The SR-4c is quite good as well.

Accuracy and Reliability of the Test

So I went shooting with different optics and kept good track of how I did.  How does that make for a meaningful evaluation of an optic?  By itself, it doesn’t.

Like rifle shooting, a good test should be accurate, meaning that it should shed light on a particular aspect of performance of the tester’s choosing.  Since this drill involved transitions, it should be a good indicator of how the optic affected the shooter’s ability to perform transitions with that optic.

Another important quality in a test is reliability of the data.  How much confidence can be placed in the findings?  I have already pointed out that it would have been a lot better with a large number of shooters doing the same drill, as this would have been more likely to provide results useful for the average shooter.  In lieu of having a large number of shooters, I had to rely on my own consistency in shooting and ability to analyze what I experience.  In this test there was a consistency issue, but I was very aware of it as it occurred.

The Beginning and the End of My Time on the Plateau

This test involved hitting a plateau in the middle of the testing and moving out of it just at the end.  The first optic I tested in this drill coincided with the first time I shot it.  That was not a great plan looking back in hindsight, but I figured at the time that the only times I would shoot the drill would be in testing.  I felt like the infrequency of shooting this drill would preclude and increase in skill.  I was wrong.

You may recall that in the Z6i test I remarked, “On runs 1 and 2 I turned in good times, but nothing out of the ordinary. Run 3 felt normal but was significantly faster for me. On run 4 I could feel that I was moving at a comparatively smoking hot pace…”  This was an instance of learning taking place.  That individual test affected the rest of the optics in this test through the T1, which was the second to last.

I left the plateau the day that I re-tested the SR-8c.  I believe this can be explained by the fact that this was the last optic in the test that I had to do ‘work’ on and collect numbers on.  As this process was new to me, and at that point I had a lot of numbers I wasn’t sure how I was going to best interpret, it was no small relief to be done with the actual tests.  I was beginning to relax.  You can actually see that in the results from Test #1, where my hit rate may have turned in a little lower than normal.  Since the tests are qualitatively different they demanded different levels of focus to shoot them well (intensity vs. open focus), and I think that is what allowed me to do so much better in the SR-8c retest in this instance.

Plateau Graph

 

Average total time

In the previous drill I think that the time was a better indicator than the hits.  In this drill I don’t think that I can assign more value to either, but will still present each as an average total time for a single run with each optic.

Test 2 Average Total Time

Taking the “plateau graph” into consideration when looking at this graph, I think what can be clearly stated is that the Aimpoint is clearly fast and that the SWFA was clearly slow in comparison to the others.  I would also speculate that since the Z6i was basically on the verge of the plateau as I entered it, it would be running closer in time to the SR-4c, but I don’t know if it would match or surpass it.

The SR-8c is an interesting case, as it came in last in the initial test and at a close second in the retest.  I would say that it would probably run a close third behind the Z6i and SR-4c.

On Paper:

SR-8c

SR-8 X Drill

Z6i

Xbox

SR-4c

Total x-box SR-4c

SWFA

Test 2 Targets

Aimpoint T1 Micro

Test 2 Aimpoint

U.S. Optics SR-8c Retest

SR-8c Recap Test 2

 Hit Rate

Test 2 Hit Rate

The graphs are interesting to me, because they make it so much easier to see things that I was not all that aware of before, even though I had the results on a spreadsheet.  The adaptation that I referenced earlier with respect to my ability to shoot this well pertained mostly to speed.  It would also seem clear that this graph somewhat coincides with the “plateau graph” above, notable exceptions being the T1 and SR-4c, which were among the fastest.  With the T1 especially, I believe that the relative lack of ability to see hampered my efforts in this drill.

Remember that I was puzzled by the overall lackluster performance of the Swarovski Z6i in Test #1.  After a lot of guessing, I made a comment, “The other thing I have wondered is if I could just see better and it caused me to be more discriminating in my decision to fire.”  I think that is close, but not quite accurate.   I think that it would be more accurate to say that each shooting problem demands a certain amount of visual information.  It might seem like more is always better in terms of the speed of observation to action (Boyd’s cycle would be a better way to understand that process), but I don’t think that is that case.  As with many other things, I think that precisely just enough information makes for the most streamlined action cycle that would arrive at an appropriate solution.  Even in test #1, while the T1 made a very respectable showing as far has hit rates, the hits were not all of as high a quality as with other optics in terms of points, which took into account the quality of the hits.  As the distance is increased and the complexity of the problem made “deeper” the requirement for information is intensified.  I believe why this is where the T1 began to show its deficiencies in comparison to the other optics.

Remember that the SWFA scope was given an accuracy boost due to my taking part in some training in the days preceding these tests with that scope.  The training addressed similar shooting problems as these.  It could not be helped, and I mention it only to aid your interpretation of the results.

I should point out the obvious in saying that the ~4.2” targets are smaller than necessary for most people’s requirements for hitting the heart/lung vital zone of a large animal.  If that is the case for you it would probably be safe to double the distances I worked at.

Average Total Points

Test 2 Total Average Points Per String

The points measure is similar to the hit ratio, except it places more weight on a center hit than an edge hit.  It also does reward 1 point to the larger circle outside the primary target.  Note that it would take several hits nearer to the center to make up for one single point shot.  The red dashed line in the graph represents the score if nine shots scored the minimum for a hit, which is 5 points per shot.

Hits Per Second

Test 2 Hits per second

Finally it becomes apparent how good my last runs with the SR-8c were in comparison to the others.  I think the graph illustrates how the U.S. Optics scopes were efficient performers.  Taking my “plateau graph” into account, I would say that the Z6i was right up there as well.  I already remarked in the SWFA individual test results how the reticle was just overwhelming my ability to receive the information I needed.  With the Aimpoint I just couldn’t see as well.

Points Per Second

Test 2 Points Per Second

In this measure the SR-4c again shows its dominance.  It just had some better hits, although its hit ratio was not as high as the SR-8c retest.

________________________________________________

In looking at the totality of the tests, if I had to actually put money down on the optimum optic for this application, multiple targets at relatively close range, I would say that the Swarovski Z6i probably has the best balance of attributes to allow the shooter to work.  I think that the two U.S. Optics scopes allow very close performance to the Z6i, with the SR-4c having a slight edge over the SR-8c.

Comparison of All Test Optics: Test #1

Links to individual test results:

U.S. Optics SR-8c, 1-8×27
Swarovski Z6i, 1-6×24
U.S. Optics SR-4c, 1-4×22
SWFA SS HD, 1-6×24

The idea for this test was simple.  How fast can I bring the rifle up, get a sight picture, and fire one shot at a close range target?  In this case 7 yards was the distance and the target size was appriximately 4.2”.

I worked at this skill prior to beginning the testing to the point that I felt that I would not endanger the validity of the testing process by doing something as egregious as easily improving my performance over the course of the tests.  I don’t believe the process was perfect, as one error over the course of 20 shots would affect my hit rate by 5%.  I don’t believe that the speed was affected as much by variables as the accuracy, as a few times I could just tell that I messed up and missed.

Speed

What I find striking is the similarity in speed between the Aimpoint T1 and the SR-4c.  Conventional wisdom says that these variable 1x scopes are almost as fast as a non-magnified red dot.  As far as speed they were basically indistinguishable.  This trend continued beyond this test and wasn’t confined to speed.

I’m also incredulous at the Z6i being the slowest.  I have doubts about what caused it, because I can’t understand why an optic with such a clear, bright image, wide field of view, minimalistic and out of the way reticle, daylight bright illumination, and generous eyebox could turn in such low numbers.  The thing is, I can’t find a me related explanation for that.

I do wonder whether some aspect of the Z6i made it slower for me in this test.  Note that both of the slowest scopes, the Z6i and the SWFA SS HD, were those that I found to have the clearest, brightest images.  The Swarovski really is just amazing to look through.  I would not be far off to say that it looks better than real life.  I wonder if it’s just a little too much to adapt to in a small amount of time.  The Aimpoint is much faster, and really isn’t impressive at all optically.  When it comes down to it though, I still simply cannot accept that the Z6i could really be that much slower.  I would need to do more work with it to believe what the results I have are showing.  The other thing I have wondered is if I could just see better and it caused me to be more discriminating in my decision to fire.

 Test 1 fastest slowest

Looking at the fastest and slowest times with each optic, I think what you are seeing is a graphic estimation of my personal maximum deviation for this test.  What I do see again, however, is that the Aimpoint and SR-4c standout from the rest and must have offered something to allow me to gain about a tenth of a second improvement over all the rest.  As for the slowest, The 1.36 of the SWFA was the 20th rep in a perfect run.  I didn’t want to ruin it.

On Paper:

SR-8c:

7 Yard Snapshots- resized

Z6i:

IMG_5792

SR-4c:

IMG_5954

SWFA SS HD 1-6×24:

IMG_6071

Aimpoint T1 Micro:

Test 1 Aimpoint

SR-8c Retest:

SR-8c Test 1 recap

I probably need to clarify again what I count as a hit in a given scoring zone, as different people have different methodologies.  In my mind, if the tip of the bullet misses the target it is not a hit, but a grazing shot.  On the other hand, if the tip is inside the scoring zone I count it.  Therefore, if over half of the bullet hole is in the scoring ring I count it as a hit.  If I couldn’t tell I give the benefit of the doubt to the shooter (me), which I think is the best policy in general.

Looking at the targets, it comes to my mind that the Swarovski got robbed of a perfect score by my trigger finger.  I didn’t take a lot of notes about the tests, so when I see that phrase “I had one wild miss due to a trigger control mishap,” I can’t help but feel as though I let it down.  That illustrates the big weakness with this test, which is me.

As I look at each target, I interpret the wide misses, such as the Z6i, the top hit on the SR-4c target, and the same type of hit on the SR-8c retest, as gross errors on my part.  I haven’t massaged the numbers to reflect this interpretation, but I just want to point it out.  I don’t know what to say about the other misses, so I just accept them.  I probably just thought I saw an acceptable sight picture and went for it.  The mistake could have come from either part of that process (the seeing or the acting).

To keep you from having to count misses and points, here are some graphs for you:

Hit Rate

The best performers in terms of hit rate were the slowest ones.  That shouldn’t be surprising.  It’s possible I just took the time I needed to get better hits.  The SWFA did have the benefit of me having had some extra practice the week leading up to the test, and I had expected a higher hit ratio than normal, although I didn’t expect a perfect one, and I expected to be faster, which I wasn’t.  There wasn’t much I could do about the extra week of shooting prior to the test.  My schedule just worked out that way.

Total Points

The points tell a similar story, although not the same, as points reward center hits as ‘better’ than edge hits.  The target also awards 1 point to an ~8″ ring in deference to the universality of the paper plate as a target (alternately read as a body shot).  Note that due to the slightly offset group of the SWFA, the Z6i still beat it in points, as 95% of the Z6i’s group was more well-centered in the sweet spot of the hit zone.  Likewise, the SR-4c and the Aimpoint run neck and neck in points, although the Aimpoint had a 5% higher hit ratio.

Because, as I pointed out when describing these tests initially, speed and accuracy are both important, I think the most telling results are those that show them factored in together.  I did this in two ways, one with points as marked on the target and one with simple hits.  Here are the hits per second:

Hit Factor

Interestingly, this was a battle between the SWFA and the SR-4c, which in this test embodied accuracy and speed respectively.  Anyone who shoots USPSA and has an eye for stage strategy will have an idea that each course of fire usually has a sweet spot in how it needs to be shot on the continuum between pure speed and pure accuracy.  In this case the accuracy won out.  It would be interesting to go back through the testing process with that bit of knowledge.

The SR-8c seems to be showing a bit of comparative weakness at close range, especially in the re-test.  The re-test really suffered due to some close misses, which really hurt its points.  I don’t think it’s performance up close was particularly bad, especially considering the versatility of the scope, but for a shooter with a bias towards the close range end of the spectrum, it would seem that other options might be preferable.

Point Factor

The points per second measure enabled a scope to make a better showing if it got some hits nearer to the center of the target.  This did make a slight bit of difference, such as with the Z6i gaining back some of its lost ground and nudging right up to the SR-4c.  The Aimpoint also loses quite a bit of its ground in this measure.  To me, that is an indication that I just couldn’t see quite as well with it, which is what I felt at the time.  Apparently I could see well enough to get a hit most of the time, but not to make those hits of higher quality, if you believe in that sort of thing.

One thing I would like to revisit is the subject of illumination.  All of the scopes except for the SWFA had daytime bright illumination in the form of a single dot, similar to the Aimpoint.  I shot this with illumination activated on all the scopes except for the SWFA.  The SWFA was one of the slower scopes.  Some might wonder how the other scopes would do without their illuminated dot.  While I didn’t run all of the scopes without illumination to test this, I did so with the SR-4c.  This was at the request of someone on an email list, so I didn’t save all the data or the target, but I do have the average time and hit rate.

SR-4c with and without illumination

The SR-4c lost some of its luster without the dot.  It was significantly harder to use, although I wouldn’t go so far as saying it was hard to use.  I don’t know exactly how meaningful this is.  I can see only a few instances in which one might have to use the optic without the dot.  The battery could be dead with no replacement handy.  The user might not have time to activate the illumination, or may have forgotten to do so.  The illumination might have timed out and turned itself off.  Of these possibilities, I did have the illumination time out a couple of times with the SR-8c and the SR-4c.  I did not experience a battery failure in either of these in the 6 months I had them here, probably due in large part to the auto shut off feature.  If the possibility of failure in the illumination system is a big issue for you, the SWFA obviously might be a good choice, and I think that the second focal plane of the Z6i would be less affected than the first focal plane reticles (with the probable exception of the SWFA) by a loss of illumination.

Which one would I choose out of these if I had to pick from one of these?  Based on the test results alone, it would appear as though the SWFA had the best balance of speed and accuracy.  I didn’t miss any shots with it after all.  After I factor in what I know about the testing process, I would pick the SR-4c or the Aimpoint for close range performance only, without making considerations for what versatility any of the scopes might add at longer ranges.  Those two are fast.  I think with more practice the accuracy could be improved, and if I’d shot with either of those at the time I shot with the SWFA, the hit ratio would likely have been better.

Thoughts on the Testing Process

Before I get into laying out the results of the tests and make comparisons for how the optics did I’d like to share some of my thoughts on the testing process, and the strengths and weaknesses of my methodology.  First of all it was a great opportunity to have access to such an array of scopes that I would likely never have access to, but for the thoughtfulness and generosity of my friend at U.S. Optics and Ilya, the optics guru/webmaster at Optics Thoughts.  This turned out to be a lot more than just a chance to get to play with what for me could be viewed as prohibitively priced “toys”, but a chance to learn a great deal about shooting, specifically the seeing part of it.

I tried to approach the tests in a way that I haven’t seen done before.  One of the reasons I started this blog was because I kept looking for information on certain topics that just didn’t seem to be available.  What I tried to do in these tests was evaluate gear not in terms of how neat it was, or how nice a certain facet of it appeared upon examination, but how the product as a whole and total thing affected specific aspects of my shooting.  Evaluating optical clarity or brightness, for example, may be important, and probably do relate to an aspect of work in the field.  But to take an optic see exactly how it performs in relation to other competing optics where the rubber hits the road, and to do it in a carefully measured and analyzed way is not something I have seen before.  This small article explains the strengths and shortcomings of my attempt.

The Bad:

The primary issue with the testing is one of sample size, in the number of shooters participating in the study (n=1).  I could also say that it would be better to have access to more samples of each scope, which it would, but I don’t think that scopes are as variable a good as, say, guitars.  Also, I wasn’t really trying to pick the scopes apart mechanically or optically, just seeing how well their designs and features enabled me to shoot.

With more shooters, the results of the tests would be much more likely to apply to other shooters.  As it is, they relate specifically to me.  That places the burden on me to explain how the subjective interacted with the objective test results.  Luckily, I think my mind is geared towards analyses such as these.  Hopefully I can bring something meaningful out of the results for you.

There were some issues with consistency in methodology.  These were mostly things that couldn’t be avoided.  My trigger broke during optic #2, test #3.  The replacement was quite different.

I wasn’t able to use the same mount for the SR-8c as I was for all the other optics.  I don’t think this turned out to be a big deal, but it was something different, and less ideal.  When I re-tested the Sr-8c there was really no need to re-adapt to it.

One of the major wildcards was me.  Originally my intent was to get up to speed with the AR so that I was at a plateau.  It turned out that I hit that pretty fast, and at a lot lower of skill than I had hoped.  Overall my level of skill was quite stable, with some unintended learning and adaptation going on in test #2, the X-Box drill.

The tests took place over a rather long span of time, probably about two and a half to three months.  I would have liked to have spent a significant amount of time with each optic, because I think that really getting to know the strengths and weaknesses of a system takes a lot of time.  The problem with all that time is that it’s hard to maintain a stagnant level of skill for that long a time.  I did my best, but the subconscious just wants to adapt.

The major differences between testing the optics themselves were that I spent a lot more time with the SR-8c than any other optic, and that the frequency of testing sped up at about the time I tested the SR-4c.  I also spent the week shooting just prior to my test of the SWFA scope, which I’m positive skewed the accuracy numbers favorably for that scope.

I made a few minor shooting errors in testing.  Larger sample sizes of shooters probably would have ironed this problem out.  There are times when I just messed up and, for example, screwed up the hit ratio in the 7 yard testing of the Swarovski Z6i.  I got my hold wrong with the SR-4c.  I used the wrong mark to hold with the SWFA scope.  Test #2 typically had at least one “short circuit” moment with each scope except for the SR-8c.  Some of those were more egregious than others.  I’ll note them in the tests.

Better ammo would have been nice, especially for the 100 yard precision test and the ‘long’ range transitions.  I do think that the XM193 is consistent, especially within the same lot, as I used for the testing.

The Good:

First of all, and most importantly, I think that the tests were valid, except for test #3, DD25.  I just couldn’t shoot it well enough to be consistent.  Otherwise I think the tests essentially got at what I wanted them to get at.  I will re-state the purpose of each test as I cover the results.

The state of the barrel’s cleanliness was extremely consistent, as I cleaned the barrel with Patch Out and Accelerator prior to beginning each round of tests.  By the time I got to the point where precision mattered, the barrel was thoroughly fouled, but not so much as to affect the precision negatively.

The tests were conducted with care to ensure uniformity in the procedure of setup and administration.  The same type of targets were used for each optic.  I shot them in the same places, at the same distances.  The times of day were generally the same.  The conditions didn’t change as much as they might have over such a large span of time.  When they did, such as the grass getting longer, I figured out ways to overcome that without compromising the tests, such as using my vehicle to shoot out of instead of the ground.

One thing I did that I haven’t discussed yet was that I tested the Aimpoint T1 Micro at the first 3 tests as sort of a non-magnified ‘control’ optic.  I also re-tested the SR-8c at the first three tests to see how my skills changed over the course of the testing process.  I’ll bring those results into play as I go over those specific tests.

Finally, for most of the tests I think that my shooting has been consistent enough to see the difference in the optics.  When I was less than consistent I’m at least able to recognize that the testing was essentially invalid, as with DD25, or when it changed, as with the X-Box test.

I realized that I’ve been throwing a lot of densely packed information out, and perhaps in not the most digestible fashion.  I decided to try to take after the format that Cal over at Precision Rifle Blog has been presenting his scope tests, which are done in a much more systematic and rigorous manner by the way.  Hopefully you’ll be able to make sense of the results, which are coming up next.

 

Dr. Scopelove, or How I Learned to Stop Worrying and Love Parallax

 

(From the undiscovered, secret “Art of the Rifle” archive vault of shooting past. I thought I would take a break from the number crunching of scope testing and write about something quick and easy. Apparently I have a mental disorder that compels me to collect and crunch numbers.)

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Parallax seems to be in the mind of more shooters as they are starting to notice that a lot of scopes have side focus knobs. There’s a knob there that says “Parallax” with yard numbers and such, so it has to be a big deal. I must have noticed that knob at some point, as evidenced by this old article on my blog.

Before I entered the abnormal mental state of coming up with numbers to crunch in relation to shot group stats, I had a different abnormal mental state of coming up with creative shooter-related diagnoses for what turned out to be a gun that needed some accuracy work. One of the things I got hung up on was parallax, as my scope on that rifle, formerly the FN PBR-XP, currently the “Mark Deux”, is not equipped with a side focus knob. Sometimes not having the means to adjust something can give one the idea that that lack of that ability is a serious and significant deficiency.

Earlier in the year I was loaned a sample of the upgraded SWFA 3-15×42. Perhaps upgraded is the wrong word, because I don’t know that it’s actually intended to replace the 3-9×42, but it would just make sense. As Nigel might say, “This one goes to fifteen. Well that’s six more, innit?” I thought it would make sense to compare them and see how that turned out.

The newer 3-15×42 has a side focus knob. One of the things I wanted to compare was whether that resulted in better capability for precision. Before I did that, I needed to establish a baseline with my tried and true 3-9×42. What follows is my submission of evidence that I actually made my journey to the dark land of parallax and returned to tell the tale…

Plan A: “No plan survives first contact with the enemy.”

Armed with the On Target TDS program and some of the proprietary targets that go with it, I set out to attempt to induce parallax error at 100 yards. Those of you who are smarter than me (only the 7,000,000,000 who have that distinction) may have already spotted the flaw.

I have to reverse engineer my grand plans to some degree, because this happened a couple months ago, but the plan seems to have been to shoot 3-4 sessions of 12 shot experiments. Each target consisted of three columns of four bulls. For those actually keeping track that’s one shot per bull. Since I had three columns, for the left column I would put my eye as far left in the scope’s eyebox as I could while still being able to see the target. For the center column I carefully aligned my eye in the center. For the right column I moved my eye to the far right. I shot them from left to right, which would mean that each group was formed in a “round robin” fashion to reduce the possibility that something would make one group better than the others due to some outside condition. After a few outings I should have collected large enough sample sizes to be able to tell something.

After shooting the 12 shots I compiled the results into three groups of four shots, one for each column, using On Target TDS. On target allows for precise measurement of group size in extreme spread and mean radius, the location of the exact group center, and the measurement of the distance of the actual group center from the point of aim in terms of horizontal, vertical, and total deviation.

The raw targets look like this:

IMG_5854;

Here are the composite groups:

Left:

Parallax Left

Center:

Parallax Center

Right:

Parallax Right

Total:

Parallax Sum

After analyzing my first target I remember being confused. In retrospect I should not have been thinking anything after only four shots on target, but I did not see what I had expected to see, which was three distinct points of impact that correlated directly to the directional change in eye position. Nothing in life ever turns out that perfect.

Later in the day I tried again with exactly the same format. This time I felt like I shot a little better. Note that in this case the group centers were all very similar. There are differences in group size, but I felt that could be easily attributable to having more difficulty with sight picture and eyestrain at the edge of the eyebox.

Left:

PM Parallax Left

Center:

PM Parallax Center

Right:

PM Parallax Right

Total:

PM Total Parallax

You might have noticed little to no shift in the point of impact in the last three shot groups and the composite total.  I noticed that too.  I now had a total of 24 rounds telling me something different than I expected. I started considering something that I should have thought of before shooting. I emailed SWFA and asked them what the parallax was set to in the scope. Skylar answered the same day with the following: “The SS 3-9 has a fixed parallax set at 100 yards. “ Trying to induce parallax error at the precise distance that the scope is set to be parallax free is not a really good idea for those of you that are sane and well-adjusted.

Plan B: Trying to induce parallax at a distance other than the factory setting.

After hearing from Skylar, I set about researching the problem a little more. I found something interesting on the internet here: http://www.longrangehunting.com/forums/f18/parallax-adjustment-scope-57372/ (scroll down to post #6 by LouBoyd).

Using his equation, RT = RS(Dt-Ds)/Ds, I figured out that at 200 yards the possible parallax error was equal to the radius of my objective lens, or approximately 0.827”. I used 200 yards because of my overdue shooting goal, which is to be able to hit a 4” target within that distance under a wide variety of conditions (understated). 0.827” isn’t much, but I decided to test at 200 anyway.

I placed three targets at 200 and shot them in round robin fashion, with 6 shots each. Here you go:

Left:

200 Parallax Left

Center:

200 Parallax Center

Right:

200 Parallax Right;

Here is a composite target of all 18 shots:

Total Parallax 200

Here is a chart of the deviation, in MOA, of each group.

Parallax Chart

Here is a chart of the mean radius if each group, also expressed in MOA:

Mean Radius Parallax Tests

After seeing that the group that should have been pretty good was not, and that the groups that should have not looked as good, but did not, and after not seeing any particular shift in point of impact, and, after seeing that my groups at 200 yards in which I tried to induce parallax were better than the groups I fired at the distance at which my scope is parallax free… I decided the following:

While parallax is a real thing, the importance of it isn’t universal to all shooters. For long range it’s going to be more important. For my purposes, there are more important things to work on, like follow through, which is what I think happened with the “center eye” target at 200. Once again, it comes down to fundamentals.

SWFA 1-6×24 HD Test Results

There were a few issues with the testing of this scope that had nothing to do with the scope.  On Monday of that week I cut my support hand badly.  I had also been doing some specific training the during the week leading up to the tests.  That put me in a time crunch so I couldn’t get stitches for my hand and the wound kept getting reopened during the training.  This training, coincidentally enough, concentrated on hitting small targets at close range.  Misses were heavily discouraged.  It was worth it to take the time to get the hit.  The day prior to the test I practiced field movement with my bolt gun and all my gear leading  up to shots on the 4”ish targets in sub-optimal terrain under time constraints.

All the other tests had nothing much going on before them, so it seems likely that the results may have been affected.  Going into the testing I expected that there could be a difference.

I also had started to shorten up the interval between scope testing at about the time I tested the SR-4c.  This was not really intentional, other than that I started feeling the pressure to get the scopes back to their owners after they were gracious enough to let me try them out and I took way too long.  My expectation going in was increased speed and accuracy on tests #1 and #2

Test 1: Single Shots at 7 Yards

I discovered upon taking sight of the targets after setting them up that I couldn’t see the illumination.  I double checked to see that it was on, which it was.  I could also tell that the reticle took on a slightly crimson hue when the illumination was on, but for all intents and purposes it was worthless.  I ran the tests with it off, which make the optic the only one of the tests to have been officially tested without illumination.  Upon reflection it would have been something worthwhile to include with all the scopes, but that is another time and money thing where a line had to be drawn.  I did shoot this course with the SR-4c without illumination as an unofficial experiment.  I’ll share those results later.

This test had the distinction of being my only completely clean run at it over the duration of all 20 shots.

IMG_6071

Test 1 numbers

In terms of speed, the SWFA 1-6×24 was in between the SR-8c and the Z6i.  The hit ratio was the best out of all the optics tested.  I don’t know how much, if any of that, to ascribe to having had a rifle in my hand for a large portion of the four days preceding the test.  In terms of the scores that factored in time, this scope was on top at that point.

What’s odd to me is that during the test it felt as though I was fighting the reticle, but I ended up shooting more accurately.  I tend to think that my level of skill was “warmer than ambient” due to the work I had done in the preceding days, but I think the only fair way to deal with that is just to take the results as they are.

Test 2: Transitions- the X-Box Drill

IMG_6085

Like test 1, I felt like I was fighting my way through this drill to some degree.  How I think it should work is that both eyes should be open and my eyes should pick up the next target and drive the point of aim to it without losing the scope’s eyebox at any time in the process.  I experienced that to the greatest degree with the Z6i.  I had a hard time maintaining the eyebox in this test.  The other thing was that I ended up shutting my left eye because I felt like I was fighting through too much information.

Test 2 Targets

Test 2 numbers

As with test 1, my hit rate was better than any of the others tested so far.  The hits per second score was 6 thousandths less than the Z6i.  The other scores were below the SR-4c and the Z6i, but above the SR-8c, which had the honor of being tested the first time I shot this drill.

Almost every time I shot this drill, I would have at least one “short circuit” type moment where I suddenly realized I was heading to the wrong target or just forgot where to go next.  This first happened with the Z6i, and I actually went to the trouble of figuring how to ‘correct’ the numbers.  At the end I’m going to leave them as I shot them but point the errors out.  Judging by the times, I had two minor “where am I going” moments that added about a half second each with this scope.  These are not as complicating as the “oh crap I’m heading to the wrong target, which one am I supposed to be going to, am I sure?” type mistakes that can add about a second and a half per mistake.

Test 3: DD25

Test 4 Targets

Test 3 Numbers

This drill was enough to unravel whatever accuracy edge I might have trained in over the course of the week leading up to it.  Again, you can see the trend that I started pushing my times at the expense of accuracy.  Eventually you’ll see a nifty graph that shows this course of fire getting progressively worse with each time I shot it.  This has nothing to do with the scopes, but perhaps something to do with my attempt to keep my skills at all these tests as static as possible in order to keep the results accurate across the board.  What actually happened was that increasing speed was paying off for me in the X-Box test and I tried to do the same thing subconsciously with this one.  This being a different type of shooting altogether, it didn’t pay off to speed up.

Test 4: Groups at 100

This was the big chink in the armor for the SWFA scope.  The target I use for this test is not really too hard to see, as it is made up of a black circle and dot on a white piece of paper.  The problem is that the circle and dot are relatively fine.  The boldness and density of the SWFA reticle made it difficult to discern the target.  This was ironic, because the SWFA’s reticle basically bracketed the target circle perfectly, the circle being 3.5”.  A mil is 3.6” at 100 yards, and factoring in the line thickness it was just about, as Ace Ventura would say, “Like a glove.

Here’s an illustration of what I was up against:

6x view

And just a bit closer to what I see:

IMG_6129
This should really be a double tripod job, one for the scope and one for the camera.  Alas, I have not a single tripod.

In contrast, I happened to have the SR-8c still on hand.  The reticle is a little more sparse, since it lacks the half mil hashes, which are not only unnecessary in my opinion, but detrimental.

At 6x:

 SR-8c at 6x

SR-8c at 6x close up

That’s what an extra $1500 will get you.  Yes the crosshairs do obscure the target center, but I believe that the line thickness may be less, and/or the reticle might not be as dark.  In any event it’s easier to see the target.  At 8x it was significantly easier as can be seen (approximately) below:

SR-8c at 8x close up

Here are the SWFA’s numbers:

 Group 1

Group 2

Group 3

30 Round Group

Test 4 Numbers

Test 5: “Long” Range Transitions

I’ll lay out the procedure for you again.  I have four targets at the following distances: 170, 230, 270, 330.  I have put them in a different order, left to right, for each optic test.  I have shot the same order, left to right, in the same way every time, in a manner that best balances the permutations for each transition.  I have a total of 36 rounds, 18 in two magazines, which gives me a total of 9 shots on each target.  I evaluated the targets in terms of points on target, group size in inches, extreme spread, mean radius, and deviation of the group center from the point of aim (horizontal, vertical, and total).

IMG_6152

IMG_6151

I had hypothesized that this optic would do very well on this test.  I have felt that the reticle is too dense for most applications, but that the density would pay off at longer ranges.  It turned out that it basically held its own against much more expensive scopes.

I made an error with the first four shots, being the first shot on each target.  Although I had known that the reticle had half mil hashes, I still reverted back to reading each has as a mil, causing my holdover to be less than it should have been.  To compensate for this I left the lowest shot from each target out when I plotted them with On Target.  This gives the SWFA scope a bit of an unfair advantage in the extreme spread numbers, but not a huge one.

Where the scope shined was in the precision of the groups.  The spoiler alert is that the SWFA showed the best average extreme spread (by 0.055 MOA) and was a close second in mean radius.  It was consistently last or second to last in terms of deviation though, which put it in third place for points.

170

230

270

330

Here are the numbers.

Test 5 Numbers

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All in all, this was a solid scope held back by a busy, “over bold” (not what happened to Mr. T- that was over gold) reticle.  Upgrading the reticle with something simpler, and daylight bright illumination would very likely put this scope’s performance up there with scopes over double the price.  In my opinion, doing all that and putting the reticle in the second focal plane would put this on my list of scopes I would buy.  Sounds quite similar to the features of the Vortex Razor 1-6, but I wasn’t able to test that scope to say for sure.

Coming up soon I will break down the performance of the scopes in each test for comparison and further analysis so you can see exactly how they compared and maybe get an idea of why.

Test Optic 4: SWFA 1-6×24 HD

IMG_6070

You might be getting sick of the scope reviews. That’s alright, because I talked with Steve and he said he liked them. Steve, if you get a chance email me about 3-Gun stuff. Back to our regularly scheduled programming.

 

I should begin by saying that prior to putting this scope on a rifle, I had been spoiled by scopes that cost $2500 (x2), and $2000. This scope, the SWFA 1-6×24 HD runs at about $1000 and I have seen it on special for about $800. I was very curious to see how it performed in comparison. I go back and forth between wanting the absolute best (typically thinking it must be the most expensive) equipment and thinking I should be able to do more with less, so this was interesting.

I received all of the scopes that I tested within a short time span, probably a few days (it was a while ago). Before I mounted any of them on a rifle I just looked through them at ‘stuff’. At the time I was very impressed with the image quality of the SWFA. Not being an optics guru, I’m not going to try to describe it in more detail than by saying I thought it was nearly the equal of the Swarovski, and noticeably brighter than the USO scopes. Temper that with the admonition that I’m not anywhere near the optics connoisseur as I am a trigger aficionado.

trigger aficionado

In the interim after receiving the scopes and before I mounted the SWFA, I spent months playing with the SR-8c, the Z6i, and the SR-4c. The SR-8c was the first one I mounted and spent the most time with. It basically set the bar, so I think I should try to explain how that bar was set.

My impression of the U.S. Optics scopes is that they are well designed, well executed, and have nothing at all gimmicky about them. I think that they are meant to fulfill the expectations of an end user who knows what he’s doing and who is willing to shell out the mackerels for the best he can get. The only trends they need to worry about are performance related. The Swarovski was similarly lacking in anything other than what would make it functionally excellent in its intended genre.

What all the high priced scopes had in common were relatively minimalistic reticles that stayed out of the way of their daylight bright illumination. It didn’t take much time on the range with these scopes to appreciate the utility of an uncluttered visual workspace. This also had an influence on how I handle mechanical offset. In my mind, having had the chance to try it, the superiority of a single illuminated dot combined with a clean, clear field of view is obvious. I disagree with some other reviewers on this, who feel that reticle trumps illumination. I, of course, am right, no matter how much I may enjoy and learn from their reviews (my wife said to make sure it’s obvious I’m joking so I don’t look like an ass).

The context of where the bar was set led me to an immediate dislike of two of the characteristics of the SWFA 1-6 as soon as I mounted it. The knobs and scope caps are unnecessarily large and the reticle is too busy. I’ll explain.

Big adjustment knobs seem to be part of some trend in the tactical scope market, particularly with precision rifle scopes. I own one of those scopes myself, the Vortex Razor 5-20×50, which practically has a beer can sized knob. I don’t think it’s that big a deal with a long range scope, but in a scope with a minimum power of 1x there are some assumptions about the venue of use, namely, it’s made for use at close range. Close range means that things happen quickly and probably dynamically. Success under those conditions calls for keeping one’s capacity for observation and adaptation so high that Scotty would be telling Captain Kirk that the ship is breaking up (“The visual circuits can’t handle much more of this!).

If for some reason the target is no longer in the field of view by the time the rifle is raised (maybe it has moved), or perhaps a second target is detected, the ability to use vision = field of view inside the scope + field of view outside the scope – field of view obstructed by rifle and scope. Therefore the lower profile the scope can be while still fulfilling its functional requirements the better.

Having said all that, although I saw the large knobs and disliked them, I think they were far enough forward to be out of view. Just to prove I’m still human, I continue to dislike them because I think they were made that way to be trendy. Everyone knows that big knobs are cool (like, duh).

The reticle was a different matter.  This was the scope I wanted to test so badly before I had the opportunity to test any of these because I thought that the reticle design was brilliant.  We’re talking about a first focal plane scope that had a big, obvious circle to line up at close range, where the big circle completely disappears when the scope is dialed up to maximum magnification!!!  The rest of the people in the running for the Nobel Prize might as well forget about it.  That was how certain I was that this was the best answer .

It was a big surprise when I finally mounted the scope on the X-15 and sighted through it. “Dang. It’s kind of hard to see the target.” It’s not precisely correct that it was hard to see a target, it would be more precise to say that there was also a lot of other stuff to see in the scope that was not the target.  I was not prepared for the reticle to come up as part of the vision = field of view inside the scope + field of view outside the scope – the field of view obstructed by the rifle and scope equation.

I also learned something about my reticle preferences for a scope in the 1-?x role.  I don’t like circles.  That’s ironic because I’ve been using an EOTech for about 8 years now.  Having used the single dot, the circle just seems to create visual noise that fulfills no actual function.  I’m not reticle ranging at close range (if ever).  I’m not using reticle holds at close range.  I don’t need to have some magical alignment circle to line up the scope, because the scope is a big circle if I look through it correctly.  All I see is that recoil creates a giant, bright, vibrating ring right smack in my field of view when maintaining a continuous sight picture in rapid fire.  The dot provides perfectly adequate usefulness with little to no uselessness.

The other primary difference with the SWFA is that the illumination isn’t always visible. The term “daylight bright” has been all the hubbub over at the yonder gun forums for a while now, and after all this scope testing I finally can concede that the concept is more than a marketing ploy.

In some situations in daylight the illumination appears to be nice and bright. Other times it just seems to wash out. Ironically, it’s the prominence of the reticle that allows for consistency in performance whether the illumination is visible or not. So in one way, the over-bold reticle can be seen as a design compromise to make up for the lack of a daylight bright dot, which would increase the cost of the scope.

The only other thing that I found even slightly wanting was that I preferred the illumination modules on the other scopes to the conventional knob on the SWFA. I think I killed two 2032 batteries in the short time I was in possession of it. Some people prefer the knob, as something that can be grabbed and turned, rather than toggled or pressed, but I liked the other scopes’ systems better.

I ended up writing about the things I didn’t like about the scope for some reason.  It would only be fair to point out that I’ve recently noticed that the way I perceived these scopes for testing was significantly different than if I had bought it myself.  Ironically I was less willing to accommodate any flaw.

I should point out that, even given the things I don’t like about it (which are also completely subjective), the scope is well made and will likely be able to fulfill the requirements is was made to.  The testing will unravel that bit.

The scope seems to be a quality piece. There were no issues in mounting or setting it up. The build quality seems very good.  Oh, and the knobs clicked like chocolate wafers atop clouds of cotton candy.  There.  No scope review is complete without going into gyrations over clicks.

Test results coming up.