As I discussed in another recent thread, I was looking for a way to stretch the effective range of my AR holdings to longer distances than my Aimpoint-sighted carbines were really suited for, but also with a gun that was lighter and handier than another of my rifles. After thought and research, including the suggestions posted there (thanks again), I settled on two major components.

The first was a Wilson Combat “Protector S” carbine. Based on advice and reviews, I expect the basic precision of the gun to be better than that of most of the carbines I own now, but I wasn’t looking for something that would allow me to snipe flies at 1000 yards. One of the advantages of the WC offering besides its reputation was that it was on sale at a significant discount that made it not too much more costly than what I was prepared to spend for an upper alone.

The second acquisition was a new scope sight to complement the carbine, and again I wanted something to fit between the capabilities of my nonmagnifying Aimpoints and a Leupold Mark 5HD 3.6-18×44mm that are mounted on other ARs. I had previously owned a 1-6× Leupold and found that 6 power wasn’t adequate to allow me to realize all the precision of the rifle it was mounted on at the time. I believe, though, that 6× will be fine for its contribution to the “platform” I have in mind. I prefer first focal plane scopes even for intermediate ranges, and the drawback of a higher magnification range such as 1-8× (or even greater!) is usually that the reticle becomes too small to see clearly at low magnifications.

Again after researching the available options I decided on the SAI* Optics 1-6×24mm scope. Factors in its favor were that it’s made in Japan and had received a favorable review by the “Dark Lord of Optics,” including his comment about how easy it was to “get behind.” That usually refers to a generous eye box, and that’s something I have come to appreciate very much as my aging body becomes less flexible and complains more about assuming certain shooting positions. SAI Optics is also part of Armament Technologies that offers the very highly rated Tangent Theta line of scopes.
* According to the box: “Speed Accuracy Integrity.” (Yes, I have no idea. Does SAI also mean something else?)

I also liked what I saw of the SAI 6 “Rapid Aiming Feature” (RAF) reticle. Reviewers remarked about how easy it was to find the center of the reticle due to the four arrow-like aiming aids that point toward the center at 30 degrees from the horizontal and that caught my attention. More common designs for LPVO reticles feature small segmented circles (like the Leupold Mark 6 I previously owned) or a “horseshoe” design that the newest Leupold Patrol 6HD 1-6×24mm scope features. At low magnification settings such small circular dot reticles in first focal plane scopes become in effect the illuminated dots of Aimpoints and similar sights. Lighted dots are very easy to pick up quickly, but they are not ideal for precision targeting (in my opinion, of course).

The RAF reticle was reportedly used in the ATN ELCAN SpecterOS 3.0 Sight, so it isn’t a completely new development.

The RAF reticle does not obscure the central crosshairs, thereby allowing greater aiming precision than a large dot. For fast aiming or when the central crosshairs cannot be seen well, centering the target within the RAF pointers centers it under the crosshairs. Using such a reticle may require a bit of mental adjustment, but I find it very intuitive. And if lighted with the illumination feature of the scope, the central crosshair section is more visible if that’s required. All in all, a reticle with more of a large central illuminated dot à la an Aimpoint or similar sight may be better for some purposes, but the RAF seems ideal for mine.





The reticle is a ballistic drop compensating (BDC) style calibrated for 62 grain 5.56mm NATO ammunition (presumably M855). If the sight is zeroed for 100 meters (not yards; it is a Canadian company product), the numbers on the vertical crosshair below the center indicate the hold over required for hits at longer ranges from 300 to 800 meters.

The BDC feature of the reticle is the one thing I’d change about the scope because I am no fan of the concept. I’d prefer simple milliradian markings below the central crosshairs like the Leupold Mark 6 1-6× offers. Rather than clutter this main discussion with my opinion about BDC reticles and how to deal with them, I’ll put that in a separate post below.

The horizontal lines of dots below the horizontal crosshair are for wind holds and are spaced at 1 milliradian intervals, as are the interval marks on the horizontal crosshair.

The last thing about the reticle is its range estimation feature. In the lower left quadrant is a series of steps that are to be used with a target that measures 30 inches high (e.g., the standard IDPA). That’s also about the distance from about the waist (or a little lower on me) to the top of the head of a man. When that measurement is fit into one of the step heights, that indicates the range in hundreds of meters: 3 for 300, 5 for 500, etc.





Optically, I couldn’t ask for anything better. The eye box does indeed seem to be very generous, and as I mentioned that’s important to me. The lowest 1× power appears to be just that, no magnification. (* Update on that. See my first post on page 2.) And although I don’t intend for the sight to be used in that role, there is no viewed image distortion when scanning quickly at close distances while clearing a room. It wouldn’t be my first choice of a sight if called upon to search a school for an active killer, but I wouldn’t take it off and leave it behind either. The viewed image is as good as I could want, but because I tend to have disrespectful thoughts when someone states that his scope has “very clear glass,” I’ll just say I can see the target, and there’s no visible barrel or pincushion distortion, and no visible chromatic aberration to serve as distractions.

The scope is provided with Tenebraex lens caps of the appropriate color to more or less match the bronze-ish color of the anodizing. I prefer Vortex lens caps, though, and that is what’s pictured on the eyepiece. (Because the Vortex caps are held in place by the pressure of their rubbery material, some people don’t like them because they can be dislodged when opening them. That’s easily prevented by a turn of electrical tape over the cap extension and scope body.)

Another thing I like about the sight is adjusting the magnification. The adjustment ring is large and requires just the right amount of effort to turn it: not too easy, not too hard. Many magnification adjustment rings require throw levers to be reasonably easy to turn, but not this one.

Because the scope is obviously designed to be used by adjusting the point of aim at different distances and in different wind conditions rather than to dial the windage and elevation for a POA = POI hold, those adjustments aren’t as convenient as they would be on a sight intended for long range precision shooting. The adjustments are capped and only a small projection is available to grasp and turn. It would have actually been nice if the scope came with some sort of small tool to fit over the projection to make turning the dials easier, especially for those of us with arthritic fingers. (I ended up fabricating an adjustment tool myself from a piece of hard plastic.)

Something that occurs to me that I probably won’t have a chance to experiment with until after we start getting daytime temperature highs above the 20s is the possibility of quickly adjusting the scope for different ammunition. In the days when we normally just set the elevation and windage and then forgot about them, the adjustments were usually mushy and without much concern about accurate tracking. The SAI 6’s adjustments, though, give the sort of audible, positive clicks that we expect from a precision riflescope. As I say, I’ll have to confirm it, but I believe it’s worth investigating.

A small plastic disk is provided as a tool for nonmarring removal and installation of the battery compartment cap, but a nickel (5¢) coin will work as well. The supplied and installed battery is the common CR2032.

Another interesting touch is the Tenebraex honeycomb antireflection device supplied with the scope. The honeycomb size is smaller than what I’m accustomed to seeing with similar ARDs, and at magnification settings of about 2× and below the mesh creates a minor visual effect (something the manual acknowledges). It’s not enough to adversely affect usability, but it is noticeable. And of course like all such antireflection devices, using it does degrade contrast and clarity of the visual image slightly.

As mentioned, the central crosshairs can be illuminated. There are nine light settings that go from being visible against light backgrounds in full sunlight to hardly visible under the darkest conditions. (Added: The illumination is not as bright as in many other scopes. The the “full sunlight” and light backgrounds comment is true only at the highest magnifications.) There is an “off” position between each numbered setting.

The scope is fairly heavy at ~768 grams (27 oz/1.69 lb). A new scope that is similar to the SAI 6 in many ways is the Leupold Patrol 6HD 1-6×24mm and that weighs 16.2 ounces per factory specifications.

There was no drama with mounting the scope except that the diameter of the magnification adjustment ring is slightly larger than what I’ve seen with other LPVO sights. That must be considered, especially with the usual AR receiver topped by a flat Picatinny mounting rail. Using Leupold Mark 4 30mm high rings left about 1/10 inch between the top of the rail and the bottom of the adjustment ring which I find to be ideal.

The Mark 4 rings are hardly necessary for use on a 223/5.56 AR and they add to a fairly heavy setup, but I don’t anticipate toting everything over the mountains and they’re what I had languishing in my spares box.

As stated, the rifle/carbine is the Wilson Combat “Protector S” model. I will try to post a range report later, but out of the box I’m very impressed with the gun. It was shipped with an M-Lok rail section and QD sling swivel socket to fit the slots in the handguard. The supplied magazine was a Lancer 10-round to satisfy our local gun rights infringement requirement. And in a first for me since I purchased an HK P7 pistol in Germany in the 1980s, the gun came with a test target. The three-shot 100 yard group with “69 grain HBT” ammunition measured about 1.1 inch center to center.

As pictured, I changed a few things about the gun. I prefer the Magpul stock and its little storage compartment is a good place to keep a spare scope battery, battery compartment tool, homemade sight adjustment tool, and a small tube of Lucas oil. I discussed the Vortex lens caps above, and plan to put one on the front as well. On order are Magpul Picatinny rail covers and M-Lok slot covers to make the handguard more comfortable to handle. The large rear section of the sight makes operating the charging handle a little tight, so I’m hoping that the larger Badger Ordnance replacement that’s also on order will make it easier.





================================

15 March 2022:

I went to the range today for a short session to at least get the sight on paper with IMI 77 grain OTM, LR, Mod 1 ammunition.

The below target was set at 50 yards and because I just wanted to just get the zero close, I shot from a wobbly folding table with a bipod and rear bag. The shots pictured were the last three of the session, so I believe that’s close enough for start. The group measured 0.344" CTC, or about 0.66 MOA. A single three-shot group proves nothing much, but it was satisfying nonetheless.





As I mentioned before the click adjustments were distinct and audible. I used a Horus milliradian reticle to determine how far to move the initial groups, and I was able to dial the final group directly in.

I’ll be going back to the range to check the trajectory of the ammunition (and others) at different ranges along with the velocities. For the moment, though, I’m more than satisfied with carbine and sight.

===========================

20 March 2022

Second range report.

I fired my agency’s patrol rifle qualification course with the carbine today and that provided a few more insights about the SAI 6 sight’s characteristics. The course consists of 30 rounds fired in seven timed stages at distances from 7 to 50 yards using a man-sized silhouette target. The fastest stage time is 2 seconds. The course isn’t especially difficult, but it tests a number of basic shooting and gun-handling skills.

As expected, the 6× magnification was a benefit over a nonmagnifying red dot reticle at 50 yards, and especially when the dot is blurry due to the shooter’s imperfect vision. High magnification is obviously a handicap at short ranges, so I dialed down to 1× (no magnification) at 25 yards and closer. As mentioned above, the SAI 6 scope has a first focal plane reticle and therefore the crosshairs become very small at low power. For fast engagements at 1× I therefore used the 30° marks that point at the central crosshairs to achieve a usable sight picture.

I usually shoot this and similar courses with Aimpoint CompML3 red dot sights and there were times when acquiring a sight picture with the SAI was a little slower even with no magnification. Although it was reviewed as having a good eye box, for whatever reason(s) I can acquire a sight picture a little faster with the Aimpoint sights. Part of that may be due to having much greater experience with the latter, but not all, I believe.

Also as mentioned above, many low power variable optics have a bright illuminated central dot in the reticle and that makes the sight picture more similar to a red dot LED sight than the SAI 6’s pattern. The sight does have provision for illuminating the center of the crosshairs, but although it is visible in daylight at its highest setting at maximum magnification, the illumination was not of any value to me with the type of shooting I was doing and as I say, I relied primarily on the reticle “pointers.”

In summary, thus far my experiences with the sight have confirmed what I anticipated about its utility at various distances. Although it’s fully usable at short ranges and will probably become more so with practice, it was sometimes slower to get on target than when using an Aimpoint red dot. Its value becomes obvious at distances beyond 25 or so yards. My next step will be to use the carbine and sight in an “intermediate range” course whose stages run from 50 to 200+ yards.

===========================

Third range report from 2 April 2022

This is probably the final configuration of the carbine for the time being. Mods:
Aero Precision scope mount
Vortex scope caps (held in place with electrical tape)
Camo Form wrap on the SAI 6 scope
Magpul M-LOK slot covers
Covers on the Picatinny rails
Two short rail sections on the bottom of the handguard. Front for bipod use; rear for bipod or tripod use
Magpul B.A.D. bolt catch lever
Badger Ordnance charging handle
Magpul PRS Lite stock. I was missing the small storage compartment of the previous stock, but then realized that the Wilson Combat grip had a capped storge space that would accommodate the lube, battery, and tool along with a couple of “save the last one for yourself” cartridges.
Impact Weapons Components limited rotation QD sling swivel socket at the far side rear (barely visible)





I hesitated posting this group because as I keep saying, single samples don’t prove much of anything, but then decided that multiple single samples might at least show a bit of a trend. The group was fired from the prone using an Atlas bipod for support and the target was at 200 yards. It was the last group from the prone of the day. Four of the shots went into a bit over an inch for about 0.55 MOA, and even with the outsider the group wasn’t too much over a minute of angle.





Although I’m very pleased with the rifle and sight at this point, the maximum 6 power magnification makes it difficult to eliminate aiming errors on small, long range targets. (I already had experience with that fact, and to reiterate the scope is not intended for long range precision use.) In addition, I was still getting accustomed to the stock and firing the gun from the prone. Lastly, I have found the IMI ammunition to be much more precise than common M193 or M855, but I do get odd flyers that I haven’t decided are due to the ammo quality or my shooting skills. So, those are my excuses anyway.

This message has been edited. Last edited by: sigfreund,

As I stated, I do not like bullet drop compensating (BDC) type reticles, but they’re not completely worthless as compared with the reticles that have no calibration markings at all and which hunters have used for generations.

First, why I don’t like them: The reason that should be obvious is that they’re calibrated for only one specific bullet trajectory. Change anything: bullet type and/or velocity it’s fired at due to different barrel length or other factor, or even atmospheric conditions, and the reticle calibration will no longer be correct. The three ranges where I commonly shoot vary in elevation by over 2000 feet, and none of them is at sea level whose conditions were used for the BDC calibration. It may be close enough, but it won’t be the same. Even if the calibration is exact, BDC reticles are not easy to use at ranges that aren’t marked. For example, where do we hold for 550 yards? (Hint: It’s not half way between 500 and 600.)

It is possible, however, to deal with the disadvantages of a BDC reticle. The easiest way, if not always the most convenient, is to shoot a particular load at the distances marked on the reticle and see where they hit. If the bullet hits a foot low when shooting at and holding for 600 yards, make note that you have to aim at the head of a 30 inch target rather than center mass. Other solutions may be obtained by using a good ballistic solver and some basic math. Whatever method you use may reveal that things aren’t off by as much as we feared. For example, and although I will have to confirm it, my calculations indicate that if I use the 300 meter mark to shoot at a 300 yard target with IMI 77 grain OTM ammunition, I’ll be off by only a couple of inches. That would be completely adequate for anything I’d engage at that distance.

So even though I’m not enamored with the BDC reticle of the SAI 6, I can live with it, especially as it was never my intent to use the sight for long range engagements. I will, however, have a long range ballistics chart available for the ammunition I use if I ever decide to do that.

Nice set up.
I like that reticle, looks like it would work pretty well on 1x

Once you figure out what their recipe is for the BDC you can figure out the subtensions and make your own.

For my ACSS reticle it's not exact but close.
Using Strelok+ it shows the BDC for 62 gr, scope height ect.
200 yds is on.
300=303
400=412
500=523
600=636

200 yds is the most I've tried it.
Hopefully the woods open back up soon and I can get out farther.

The WC upper looks as I expect it should. Hopefully you'll experience the same reliability and accuracy that I do with Wilson rifles.

I don't know anything about the SAI scope. Over time you'll find out how the BDC calculations work for your ammo.

I noticed that you mounted that scope much further aft than I do with AR scopes. The rear of my scopes tend to be right over the rear portion of the charging handle, although some are maybe 1/4" to 1/2" aft of the CH.

I may have to adjust the position of the scope.
It’s as far forward as possible with the one ring ahead of the adjustments without putting the ring on the handguard which I don’t want to do.

I could put the front ring behind the adjustments, but they would be closer together than I’m accustomed to doing. Comments?

I’ve seen the scope mounted with a sort of cantilever mount, but I was hoping to get by with the rings I had available.

Also, the scope seems to be about where it needs to be for my head position on the stock, but that’s somewhat variable.

Any suggestions?

ADM has nice mounts and are 1.47" if you like the lower ones.
https://www.primaryarms.com/am...t-30mm-ad-recon-x-30
Most are around 1.5" center line to top of the rail.

I have one from Swamp fox that's 1.6" that I use for my LPVO
Midwest Industries looks to have nice mounts, I'm looking at them for a 34mm 1.93" mount.

quote:

Originally posted by powermad:
ADM has nice mounts and are 1.47" if you like the lower ones.

Thanks. I believe I should look at them.

After the observation by fritz I started handling the carbine again and although the position of the scope is fine for a fully upright head position, I’ll have to try some other positions as well. I don’t expect to use it in the prone very much, and haven’t even lowered my old, creaky body down to check it yet, but that could be a problem with where it is now. I probably would have realized all this in time, but it’s better that it’s sooner than later.

If anyone else has specific suggestions about cantilever mounts, please chime in.

There are a few decent brands of one-piece mounts with a forward cantilever. I'd have to check my ARs for the names -- but it's getting late for tomorrow's early start.

My favorite is from Nightforce, and it's on most of my ARs. The NF is a taller mount, which will provide more clearance between your charging handle and the rear end of the scope. This also means a slightly more heads up cheek weld with many buttstocks.

If you go this route, you likely won't be using the fully extended position on your buttstock for all shooting positions. For example, you may end up moving to a shorter length for standing off-hand.

Thanks again, fritz. Your comments are always helpful (well, most of the time ).

I finally got into my dry fire routine using the WC in the prone and found that the scope is mounted just where I need it, at least in a short session. As pointed out, it is pretty far to the rear, but when I work up the gumption to spend time at the range again I’ll experiment with different stock extension lengths while actually trying to hit a target.

I will definitely keep the Nightforce mounts in mind, though, if it comes to that. (I didn’t even know that they had their own line.)

fritz, your observation about the position of the scope was excellent advice. After experimenting with different scope positions and stock extensions, it became obvious you were right and I now have a cantilever mount on order. As always, thank you!

Second range report at the end of the first post.

Nice !!! The WC group looks great, I can't wait for 100 yard update.
I have a WC PPE sitting at my local ffl hoping to pick up today.
Like you I wasn't specifically looking for a WC, but price was down so far from MSRP I had to try it. Was leaning towards a BCM or DD but stumbled over the WC at a better price.

quote:

Originally posted by sigfreund:
As I stated, I do not like bullet drop compensating (BDC) type reticles, but they’re not completely worthless as compared with the reticles that have no calibration markings at all and which hunters have used for generations.

First, why I don’t like them: The reason that should be obvious is that they’re calibrated for only one specific bullet trajectory. Change anything: bullet type and/or velocity it’s fired at due to different barrel length or other factor, or even atmospheric conditions, and the reticle calibration will no longer be correct. The three ranges where I commonly shoot vary in elevation by over 2000 feet, and none of them is at sea level whose conditions were used for the BDC calibration. It may be close enough, but it won’t be the same. Even if the calibration is exact, BDC reticles are not easy to use at ranges that aren’t marked. For example, where do we hold for 550 yards? (Hint: It’s not half way between 500 and 600.)

It is possible, however, to deal with the disadvantages of a BDC reticle. The easiest way, if not always the most convenient, is to shoot a particular load at the distances marked on the reticle and see where they hit. If the bullet hits a foot low when shooting at and holding for 600 yards, make note that you have to aim at the head of a 30 inch target rather than center mass. Other solutions may be obtained by using a good ballistic solver and some basic math. Whatever method you use may reveal that things aren’t off by as much as we feared. For example, and although I will have to confirm it, my calculations indicate that if I use the 300 meter mark to shoot at a 300 yard target with IMI 77 grain OTM ammunition, I’ll be off by only a couple of inches. That would be completely adequate for anything I’d engage at that distance.

So even though I’m not enamored with the BDC reticle of the SAI 6, I can live with it, especially as it was never my intent to use the sight for long range engagements. I will, however, have a long range ballistics chart available for the ammunition I use if I ever decide to do that.

I have a different method for dealing with a BDC that doesn't line up perfectly with the trajectory of the chosen bullet.


Fit the curve of the bullet to the BDC by adjusting zero distance.


For example:


For practical rifle targets. IDPA/IPSC paper, steel of varying sizes, let's say all 4MOA or larger at reasonable distances. The exact distance at which you establish your distance does not matter. For some reason we are all enamored with zeroing at a round number.

If you are zeroed for 230 yards, instead of 200 yards, you will never realize that discrepancy while shooting practical size targets at 100 or 200 yards.


But it DOES matter if your BDC is off significantly at longer distances. So, pick the mid-range of the engagement distances. For me, my 1-6 is for 3 gun and 600 yards is tops. So, zero your 400 yard stadia line at 400 yards. Or 500 at 500, play with the curves in Strelok and see which zero gives you the best fit. So now you have 'trued' your zero to maximize the utility of the BDC. Your 500 yard stadia is a perfect 500 yard zero. 400 and 600 may be slightly off, but not enough to matter on practical targets. You 200 yard zero may be off by and inch or three. It matters not, a 1-6x with a BDC is not designed for shooting golf balls at 100 or 200 yards.


Anything cartridge within the same realm of trajectory can be fitted this way. 77gr 5.56 ammo for a BDC designed for 55gr, not a problem. 150gr 308 paired with that same 5.56 reticle, not a problem.

It won't work for something like 300 blk subsonics, but again, that's a whole different cartridge and not really relevant at extended ranges anyways.

quote:

Originally posted by sigfreund:
For example, where do we hold for 550 yards? (Hint: It’s not half way between 500 and 600.)

At 3 gun matches I round every single target to the nearest 50 yards and use that hold, and yes I do visually hold half way between 500 and 600.

The sizes of targets, the improvised positions, the physical exertion, etc.... there is so much going on that it is beneficial to simplify the mental portion of it to a point where you can't screw it up by trying to remember too much detail.



I make no mental notes of any target that is closer than 225 yards. All of those are hold center.

Any targets that are farther than that get simplified to the nearest 50 yard.

Example

rifle targets on a stage include

5 paper from 10-35 yards.
1 rifle plate rack of ten plates all at 130 yards.
4 rifle BC targets shot while moving down range, distances from 160-215 yards, none of them the same.
5 rifle targets shot from a final static position, rifle rested on a stack of tires

230 yards, 318 yards, 280 yards, 405 yards, 511 yards.


Wow! That's a lot to remember and a lot of dope to calculate, right? Nope.

Every single target before the final position is simple, 'Hold Center'. None of the difference matters more than breaking a clean shot.

Final array:

Holds - 250, 300, 300, 400, 500.

Thanks for all that, IndianaBoy; excellent information that I will keep in mind as I experiment with settings.
Update at the bottom of the first post.

quote:

Originally posted by sigfreund:
Thanks for all that, IndianaBoy; excellent information that I will keep in mind as I experiment with settings.
Update at the bottom of the first post.

The best trick I have found for getting good groups with irons or low magnification scopes at longer ranges:

Use a very high contrast target, and use the entire target as your aiming point. The small black block inside a white block inside a gray block may not be ideal for trying to resolve a great target/reticle image at 500 yards.

I like using a 1 or 2 MOA white square on a contrasting black or brown cardboard backer. You aren't trying to resolve some small low contrast feature on your target now, you are just focusing on centering the stadia line in question in the very middle of that larger white target. The human eye is pretty good at seeing when something is centered on that small of a template.

With Strelok+ you can play with the zero offset as noted to get a close BDC.
This is for 69gn zeroed .5" high at 100 yds.

Thanks for the comments.

I don’t have much opportunity to shoot much beyond 200 or so yards, but I’ll keep the target suggestion in mind. The smaller targets pictured above actually work pretty well. The small black diamond works as a precise aiming point at 50 yards, and at 200 the central section of the SAI 6 crosshairs matches the size of the target very well. But some point of aim variance is possible, so I may increase the size of the central diamond so it’s large enough to see at longer distances.

I haven’t done anything with the BDC part of the scope’s reticle because as I say I don’t have much opportunity to shoot at the longer distances. I need to go to the range that’s in driving distance that has 600 yard targets to explore all that.

I appreciate the insights.

A report about using Speer 75 grain Gold Dot ammunition with the carbine:
https://sigforum.com/eve/forum...0601935/m/9600070394

Just FWIW for anyone interested in a Wilson Protector Carbine the Schools in The Colony Texas had both Black and FDE rifles marked down from $2099 to $1599. At the time they said they had 20 FDE in Stock (19 after I left). I haven't checked this weekend but they likely have several left at a good price if anyone is looking for one............dj