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 (sarcastic
          understatement?  Yes!!!).
-Clear, bright glass
-Second focal plane reticle preferred
-I’ll also add in low profile capped turrets.  I don’t plan on touching them other than zeroing
          and I’d rather not run the risk of having them bumped and affecting my zero.

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 is 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.