I have a AR style rifle, 16" 1:9 twist barrel with a Burris MTAC 1-4x24mm scope. I bought it for the express purpose to attend a 4-day Practical Rifle course at Front Sight, Pahrump, NV, last year. While my sole Appleseed experience (at that time) was helpful in my course at Front Sight, I was not at all happy with my 200 yd KD shooting performance (to date, my only experience with KD!) during my class. There were 48 students in that class, and about 45 of them were shooting an AR variant with some type of optic. Out on the range, I overheard somebody mention that
Quote"POI can change with magnification on some of these scopes."
Since I was using increasing magnification with increasing distance: 1x for shots out to 50 yds, 2x at 100 yds, and 4x at 200 yds, that comment piqued my interest.
One issue I had trying to use the MTAC reticle for a 25 yd Appleseed, in the first place, was the aiming dot. At 1x magnification, it is about 9.6 MOA!! I'll include a picture to illustrate the reticle, here:
(http://tinyurl.com/nlulboa)
While I cannot find a source at Burris.com to confirm it, empirically, I have figured out that the mil and MOA measurements shown here are only accurate for 4X magnification. So I suspect you can easily imagine that the 9.6 MOA aiming dot (at 1X magnification) completely covers up the 4 MOA squares more than two times over, making assurance of a precise POA impossible!
I devised a test to see if my POI changed with magnification and distance, and the net result was "yes" and "yes"! My test involved using some custom diamond shape targets that I designed to allow precise positioning of the aiming dot inside (or overlapping, depending on magnification) the diamond. I got very good results from this target design, achieving same-hole 3-shot groups out to 50 yd and slightly over 1 MOA groups at 100 yd at all magnifications. My test consisted of firing 3, 3-shot groups at each of 3 distances: 25, 50, and 100 yd. At each distance, I employed 3 different magnifications: 1X, 2X, and 4X. All total, each test required 27 rounds (not counting the rounds to warm-up the barrel).
My test on 28Dec13 showed an interesting trend of shots trending from R-to-L from 25 to 100 yd (using a 50 yd zero).
(http://tinyurl.com/numk4sd)
(http://tinyurl.com/nf6z5ct)
(http://tinyurl.com/payhq6n)
After much consternation and puzzling over this result, late one night, I awoke with a hypothesis: what if the scope base is misaligned with the bore axis? I couldn't sleep, so I got up and wrote out this hypothesis:
(http://tinyurl.com/norysfm)
The gist of this is that I calculated that I needed to shift my scope to the right about 0.006" (not 0.06"--oops!) to correct the issue. I guesstimate that I actually shifted it closer to 0.007", instead, but I fouled up my empirical measurements, so I can't be sure--but it is shifted to the right, to some degree! And my next trip to the range proved my hypothesis correct. While my groups were not quite as tight as those posted, the net change was that the POI error, if any, was consistent L-to-R at all magnifications and at all distances. So I believe my problem is solved! Yay!!! ^:)^
One more thing: I also figured out how to "aim small miss small" with this MTAC reticle. Since for a 50 yd zero, my expected POI at 25 yds is about 1.25" low, I need to employ hold-over. I just works out that I can use the 300 yd aiming dot at 4X@25 yd and get a sub-MOA result (from the gun, that is ;-).
(http://tinyurl.com/pd8x6ny)
Now I just need to take 'er out and prove it in an AQT! I'm hoping to do just that at a KD Appleseed event on 8Feb14. Wish me luck!
Unless your scope is a first-focal plane (FFP) reticle scope, i.e., unless the reticle gets larger and smaller as you turn the magnification knob, then the reticle subtensions will indeed be different in size at different magnification. Typically such scopes are only useful for ranging at their maximum magnification (unless stated otherwise).
Interesting results. About being off-axis with the receiver, however, you should also take parallax into account -- at different ranges, if your eye is not quite aligned with the scope, it will have an effect on your POI that is roughly linear with range. Centerfire scopes without parallax adjustment are typically preset to be parallax-free at 200 meters, but either closer or farther there will be some parallax to deal with.
Parallax can affect both elevation and windage equally. The parallax may also be affected by magnification... Therefore, rather than aligning the scope with your bore, you may have aligned it with your normal head position.
Nice groups, by the way. :---
Just out of curiosity: What kind of groups are you getting with Iron Sights at full distance?
I had an MTAC for a while, but sold it as I thought the reticle was not precise enough for long range targets and too busy for close targets. Just my 0.02 FRNs.
Quote from: b1rdd0g on January 26, 2014, 12:18:51 AM
The gist of this is that I calculated that I needed to shift my scope to the right about 0.006" (not 0.06"--oops!) to correct the issue.
Are you sure it wasn't canting the rifle or the scope not perfectly vertical in the rings? At a typical AR sight height of 2.5", 0.006" is about 0.14 degrees or 8 moa. So, if your scope was rotated 8moa in the rings and you then hold the rifle so the reticle is vertical, you will cause the scope to be offset 0.006" from straight above the rifle. Same effect if the rifle was held canted by 0.006".
The best way to ensure the scope is directly above the bore is to take a piece of cardboard with a straight line on it then poke a cleaning rod that fits your bore size through the cardboard directly on the line. Now, slide the cleaning rod down the barrel (rifle unloaded of course!). Look through the scope and rotate the cardboard so the line goes straight through the center of the reticle (the 100yd aimng point in this case) then rotate the scope in the rings so the reticle is square to the line and tighten down. At this point, if the rifle is held so the reticle is vertical to the world, the rifle barrel will be directly underneath the scope.
Quote from: Rocket Man on January 26, 2014, 04:40:14 AM
Unless your scope is a first-focal plane (FFP) reticle scope, i.e., unless the reticle gets larger and smaller as you turn the magnification knob, then the reticle subtensions will indeed be different in size at different magnification. Typically such scopes are only useful for ranging at their maximum magnification (unless stated otherwise).
Interesting results. About being off-axis with the receiver, however, you should also take parallax into account -- at different ranges, if your eye is not quite aligned with the scope, it will have an effect on your POI that is roughly linear with range. Centerfire scopes without parallax adjustment are typically preset to be parallax-free at 200 meters, but either closer or farther there will be some parallax to deal with.
Parallax can affect both elevation and windage equally. The parallax may also be affected by magnification... Therefore, rather than aligning the scope with your bore, you may have aligned it with your normal head position.
Nice groups, by the way. :---
Yea, definitely not a FFP scope. What is confusing, though, is that this scope has a companion in the same model that is 1.5-6x42 and shares the exact same reticle. The question I have of Burris is: at what magnification do the stated subtensions apply? In my case, you are correct, they hold true for the full 4X magnification. Are those same subtensions correct for the 6X magnification on the other model?? Or at 4X on both scopes?? I cannot say, since I only own the 1-4x24 scope.
As far as parallax and the nice groups, keep in mind that this is firing from a steady rifle rest on a bench, so most of the human error elements are removed or drastically diminished--I can't take credit for that. And this scope is definitely NOT parallax free, as it does not have an adjustable objective. However, since I have the gun in a rifle rest, I can be very careful to make certain that the scope shadow is perfectly even all the way around, thus minimizing the parallax effect.
Quote from: DEH on January 26, 2014, 05:12:05 PM
Just out of curiosity: What kind of groups are you getting with Iron Sights at full distance?
I had an MTAC for a while, but sold it as I thought the reticle was not precise enough for long range targets and too busy for close targets. Just my 0.02 FRNs.
DEH, um...what iron sights? No, seriously, I am so far sighted, now, that I can't bring the front sight (neither of them, actually <sic>!) into sharp focus. However, I did manage to just barely eek an expert score (214) with Tech Sights on my Marlin 795 at my last AS (as a student). It was like trying to aim using a front sight that looked like a gopher with a bad hair day! :-\ I do have some BUIS on there, though, and in fact, I even removed the MTAC, briefly, to shoot with them a few rounds at 25 yds--not bad groups, either! But I have to put on reading glasses to be able to see the front sight, at all, and then the target is so blurry I can scarcely make out my sight picture. I'm afraid using irons would not help to clarify the issue, for me, unless somebody else was shooting it. Depending what glasses I am wearing, I can see either the target or the front sight, but not both beyond 25 yds.
As for not being precise enough for long range, I might have to disagree regarding the MTAC CQ reticle. Well, clearly, there is such latitude in reticle choices that there exists a wide range of personal choices available. I found the MTAC CQ reticle to be the right balance, for me. I found red dot sights to be limiting, and way too imprecise (4 MOA dot, on my Burris FastFire II). Furthermore, notwithstanding the 4 MOA dot, I couldn't get that reflex sight to hold zero, anyway. Red dots are quick on target, though! And that is what they are designed for.
The MTAC CQ is an effort to split the difference between the two. For CQB, the scope will be set to 1X, and you can (optionally) switch on the lighted reticle (it is otherwise black, just like conventional duplex cross-hairs), place the tiny (now lit up) red reticle in COM and press the trigger--just like with a red dot, though arguably more "busy" and not parallax free. But if you need to take longer shots at man sized targets, you can still do so out to 400 yds, or so--which is getting to be about the effective limit for the carbine length barrel in this cartridge, anyway.
What you cannot do, effectively, (with either the MTAC CQ or a red dot) is fire at sub-man-sized targets (i.e. crow, gopher, bullseye, etc.) at distance. That is why I had to develop some fairly large diamond shaped targets in order to get tight groups, because no one can precisely aim at a 2 MOA target with a 4 MOA aiming dot. In that scenario, your sight picture, alone, is handicapped by +/- 2 MOA, nevermind how well you do on the 6 steps and SHF.
Quote from: Caliper on January 26, 2014, 07:08:51 PM
The best way to ensure the scope is directly above the bore is to take a piece of cardboard with a straight line on it then poke a cleaning rod that fits your bore size through the cardboard directly on the line. Now, slide the cleaning rod down the barrel (rifle unloaded of course!). Look through the scope and rotate the cardboard so the line goes straight through the center of the reticle (the 100yd aimng point in this case) then rotate the scope in the rings so the reticle is square to the line and tighten down. At this point, if the rifle is held so the reticle is vertical to the world, the rifle barrel will be directly underneath the scope.
Thanks for this tip, Caliper! :bow: I'm going to have to try this one and get back to you on how well that seems to work.
Updated 28Jan14
Caliper, I took your advice and made a cardboard reticle leveling tool--Rube Goldberg would be so proud! I found that a stylus from an old Palm Pilot worked perfectly, without modification. Borrowed some shiny cardboard from my wife, and then taped a line level across the top to keep it plumb. Finally, I used a couple strong magnets to hold the cardboard snug against the flash hider.
I laid the rifle in my steady rest and wedged it in with a rag to keep it still. As far as I can tell, the reticle is perfectly plumb. It is really tricky to tell, with this reticle, though, as it covers but a small area of the total area inside the FOV. This isn't a duplex or simplex reticle. And the parallax plays havoc, as well. But near as I can tell, the scope is level. I'll include a couple pics of my scope alignment card setup:
(http://tinyurl.com/oh89pl4)
(http://tinyurl.com/prakmpb)
Quote from: DEH on January 26, 2014, 05:12:05 PM
I had an MTAC for a while, but sold it as I thought the reticle was not precise enough for long range targets and too busy for close targets. Just my 0.02 FRNs.
I used mine last year for 3 Gun matches, and I had the exact same feeling. Thinking I will retire the MTAC this year and try a more standard red dot. I've used and liked the Primary Arms classic 30mm red dot (it's an Aimpoint clone, basically), but does anyone have a red dot they like? Not totally opposed to spending some more money if I need to, but I don't want to spend more money than I have to. Does that makes sense?
Agrivere
I have a TAC30 with the same reticle, and absolutely love it. I have used it in several cross country run 'n gun competitions, and it never disappoints. The fat 100 yd. aiming point doesn't bother me, because anything I am shooting at 100 yds. will be bigger than the dot. The ones for smaller distances are smaller. No, it would not be good for shooting small paper bullseyes, but it is great for practical field shooting. I recently moved it from my 5.56 to my .308 AR. It is a great battle rifle optic. The reticle works great on man-sized targets out to 500 yards. Yep, just use the 300 yd. aiming point at 25m. The only time I use it on 1x is for close range shooting, like 50 yds. and under.
Quote from: henschman on January 27, 2014, 11:23:06 PM
I have a TAC30 with the same reticle, and absolutely love it. I have used it in several cross country run 'n gun competitions, and it never disappoints. The fat 100 yd. aiming point doesn't bother me, because anything I am shooting at 100 yds. will be bigger than the dot. The ones for smaller distances are smaller. No, it would not be good for shooting small paper bullseyes, but it is great for practical field shooting. I recently moved it from my 5.56 to my .308 AR. It is a great battle rifle optic. The reticle works great on man-sized targets out to 500 yards. Yep, just use the 300 yd. aiming point at 25m. The only time I use it on 1x is for close range shooting, like 50 yds. and under.
Henschman, I agree completely. This scope is "fit for purpose". And that purpose is NOT shooting whiskers off of flies! It is perfectly well suited for CQB, but with "adaptability" sufficient to other purposes, including longer range (out to maximum effective carbine range, arguably) shots on man-sized targets. And as I have recently figured out, it is also suitable for AS, by using the 300 yd aiming point and 4X magnification for targets at 25 yd. Quite a versatile package, really.
I've got an Aimpoint Comp M4, the same as the current issued red dot, and it will turn down in effective dot size.
It has a 2 MOA dot, and obviously works good enough for military use. It's predecessor was also an AImpoint, with a 4 MOA dot. I'm sure they switched sizes for good reason. And, I've seen a guy with an AR (M4) get consistent hits on silhouettes at 800 meters Comp M4 sight.
Quote from: Agrivere on January 27, 2014, 07:22:56 PM
Quote from: DEH on January 26, 2014, 05:12:05 PM
I had an MTAC for a while, but sold it as I thought the reticle was not precise enough for long range targets and too busy for close targets. Just my 0.02 FRNs.
I used mine last year for 3 Gun matches, and I had the exact same feeling. Thinking I will retire the MTAC this year and try a more standard red dot. I've used and liked the Primary Arms classic 30mm red dot (it's an Aimpoint clone, basically), but does anyone have a red dot they like? Not totally opposed to spending some more money if I need to, but I don't want to spend more money than I have to. Does that makes sense?
Agrivere
For standard red dots it's Aimpoint with a 2 moa dot. Though 4 moa is adequate. Aimpoint because of proven durability and battery life measured in years. Less expensive red dots always seem to stop working at the least opportune moments.
If you want magnified then Leupold has their Firedot technology in many of their scopes. About 2 moa and enhanced battery life. Check out their VXR and VXR tactical line.
Quote from: b1rdd0g on January 27, 2014, 12:43:25 AM
Quote from: DEH on January 26, 2014, 05:12:05 PM
Just out of curiosity: What kind of groups are you getting with Iron Sights at full distance?
I had an MTAC for a while, but sold it as I thought the reticle was not precise enough for long range targets and too busy for close targets. Just my 0.02 FRNs.
DEH, um...what iron sights? No, seriously, I am so far sighted, now, that I can't bring the front sight (neither of them, actually <sic>!) into sharp focus. However, I did manage to just barely eek an expert score (214) with Tech Sights on my Marlin 795 at my last AS (as a student). It was like trying to aim using a front sight that looked like a gopher with a bad hair day! :-\ I do have some BUIS on there, though, and in fact, I even removed the MTAC, briefly, to shoot with them a few rounds at 25 yds--not bad groups, either! But I have to put on reading glasses to be able to see the front sight, at all, and then the target is so blurry I can scarcely make out my sight picture. I'm afraid using irons would not help to clarify the issue, for me, unless somebody else was shooting it. Depending what glasses I am wearing, I can see either the target or the front sight, but not both beyond 25 yds.
As for not being precise enough for long range, I might have to disagree regarding the MTAC CQ reticle. Well, clearly, there is such latitude in reticle choices that there exists a wide range of personal choices available. I found the MTAC CQ reticle to be the right balance, for me. I found red dot sights to be limiting, and way too imprecise (4 MOA dot, on my Burris FastFire II). Furthermore, notwithstanding the 4 MOA dot, I couldn't get that reflex sight to hold zero, anyway. Red dots are quick on target, though! And that is what they are designed for.
The MTAC CQ is an effort to split the difference between the two. For CQB, the scope will be set to 1X, and you can (optionally) switch on the lighted reticle (it is otherwise black, just like conventional duplex cross-hairs), place the tiny (now lit up) red reticle in COM and press the trigger--just like with a red dot, though arguably more "busy" and not parallax free. But if you need to take longer shots at man sized targets, you can still do so out to 400 yds, or so--which is getting to be about the effective limit for the carbine length barrel in this cartridge, anyway.
What you cannot do, effectively, (with either the MTAC CQ or a red dot) is fire at sub-man-sized targets (i.e. crow, gopher, bullseye, etc.) at distance. That is why I had to develop some fairly large diamond shaped targets in order to get tight groups, because no one can precisely aim at a 2 MOA target with a 4 MOA aiming dot. In that scenario, your sight picture, alone, is handicapped by +/- 2 MOA, nevermind how well you do on the 6 steps and SHF.
I was asking about the iron sight groups to assess some things. One: How often you have shot iron sights. Irons require more consistency than scopes and people sometimes seems to think that you don't have to have any consistency with your sight alignment on a scope, BUT inside the parallax distance (and even beyond sometimes) you still have to be consistent.
Two: If you have shot irons a lot you probably have developed the ability to focus intently on one thing. SOMETIMES and with certain reticles it is difficult to focus on one thing which contributes to larger shot groups.
I understand about not being able to see the front sight on a 16 inch. I have difficulty with 16 inch carbine length, but have found that the mid length 16 inch to have a far enough sight radius that the front sight is clear. I dunno if you have tried a 20 inch, but you may have better success with a longer sight radius.
As to optics, I'm of mixed emotions on Leupold. Mind you, I have several examples of their top of the line scopes, though from just a very few years ago. 36 power competition scopes, to be more precise.
Great stuff, as long as you don't go to use them or adjust them in what some folks call extreme cold. I have seen several Leupold scopes fail at -25 degrees, at a match in northeastern NY (Dunham's Bay). My Weaver didn't fail, nor did Seeley's Bausch & Lomb. I had to adjust parallax and zero. That was a steel tubed El Paso Weaver, not the current ones.
DEH, it's real easy to just focus on one plane. That's all the eye will focus on, never two or more, just one. Younger eyes deceive us and we think we can focus on two, but we learn better than that as we age.
Me, I found I really need optics. I don't need the magnification so much as I need the optical focal plane. It's apparently an astigmatism thing.
Quote from: b1rdd0g on January 27, 2014, 12:47:01 AM
Caliper, I took your advice and made a cardboard reticle leveling tool--Rube Goldberg would be so proud! I found that a stylus from an old Palm Pilot worked perfectly, without modification. Borrowed some shiny cardboard from my wife, and then taped a line level across the top to keep it plumb. Finally, I used a couple strong magnets to hold the cardboard snug against the flash hider.
Actually, the beauty of this is you don't need a level. What you are doing is drawing a straight line between the center of the bore and the center of the scope and aligning the reticle to that.
Thinking about it, a better way to test if POI changes with magnification is shoot at the same distance using different magnification. That way, you'll be able to see any windage or elevaton changes without the added variable of drop at range.
Quote from: Nickle on January 28, 2014, 10:25:50 PM
As to optics, I'm of mixed emotions on Leupold. Mind you, I have several examples of their top of the line scopes, though from just a very few years ago. 36 power competition scopes, to be more precise.
Great stuff, as long as you don't go to use them or adjust them in what some folks call extreme cold. I have seen several Leupold scopes fail at -25 degrees, at a match in northeastern NY (Dunham's Bay). My Weaver didn't fail, nor did Seeley's Bausch & Lomb. I had to adjust parallax and zero. That was a steel tubed El Paso Weaver, not the current ones.
DEH, it's real easy to just focus on one plane. That's all the eye will focus on, never two or more, just one. Younger eyes deceive us and we think we can focus on two, but we learn better than that as we age.
Me, I found I really need optics. I don't need the magnification so much as I need the optical focal plane. It's apparently an astigmatism thing.
You are correct: It is easy to focus on one plane assuming they eyes are still capable of enough accomodation to see clearly. What I was talking about was the ability to focus on one object/thing/point. I have found that the smallest object that can be seen clearly typically produces the tightest shot groups. Granted, that is highly subjective depending on the factors that affect the accomodation of the shooters eyes such as age, astigmatism, etc. I have noticed in NRA Highpower shooters that the older they get, they wider the front sight post gets. While the optics give you one focal plane, it is sometimes difficult to focus on one thing on the reticle (depending on what kind of reticle you have) Some reticles have extremely large crosshairs or BDC's which can prove challenging for some people.
The convers of this of course is since you can see the target much more clearly and movement is magnified by the scope, people tend to fuss the shot more.
All of this is highly subjective of course so YMMV.
Some pretty clear and correct observations there.
Anyone that has used a benchrest scope can tell you that they aren't usually cluttered with all the popular "doo-dads". A real good one for competition might have a fine cross hair and a small dot. They just simply don't use BDC's, as they aren't ever going to be accurate enough. So, they know their loads trajectory and use come-ups (hmm, ever hear that before?).
I've been long known for keeping the scope power way down for position shooting. Matter of fact, no more magnification than is needed, 2 power is OK, 1 power (no magnification) is better. Why do I say that? Well, as DEH said, higher magnifications cause "fussing the shot".
My favorite scopes to use, when I use optics (usually) for position work are 2-7 power variables, cranked down to 2 power. To me, the magnification is on the high side, but tolerable.
There are exceptions to that.
My AR wears a 4 power ACOG. That won't change.
My target rifles wear either 6 or 36 power scopes. They are shot in competition, from a rest and bags. They are about 100% useless for position shooting, other than the 6 power rifles in prone. Weight and balance are all wrong for position.
The bottom line is clear. Use the right tool for the job.
I also love the Aimpoints. My 5.56 has an old Comp M on it with the old 3 MOA dot. I keep it zeroed for 50 yds./200m, and with that setting, it works great for anything 300m and under. That is where the vast majority of shots are going to be taken at. For anything farther out, the method that works best with me is to just flip up my rear sight and use the irons right through the tube of the Aimpoint. I have a KAC rear sight that is fully adjustable in 1 MOA clicks for elevation, so it's easy to go to the sight setting I need.
I really want to replace this older Aimpoint with an Aimpoint PRO. It has improved clarity, a 2 MOA dot, is night vision compatible, and has a 3 year battery life with the dot constantly on. They are normally around $400, button can usually find someone with them on sale for around $350-360. Palmetto State is running a good discount on them right now.
Tactical/red dot/AR scopes are generally (there are exceptions) geared towards CQB (and marketing to everybody who wants to fire lots of rounds at big targets and look cool). They are not intended for precision shooting at longer ranges although they may advertise features that sound "long-range." The fundamental problems mentioned above, especially aiming point too large are fundamentally contrary to precision shooting. The optics utilized by SWAT and military operators are designed for modern combat ranges and greatly increase the effectiveness of those operators over relatively short engagement ranges.
If you want an SDMR, put an SDMR scope on it. NATO and Soviet type SDMR optics ARE designed for extended engagement ranges with appropriate ranging reticles and somewhat useful BDC and windage compensation devices. I've found the Soviet PSOP types to be especially effective. I also had a NATO Stanag scope on a FAL at one time and that thing was ridiculously good. Best of luck.
If you're looking for a damn good red dot, I scored my Rifleman at my first Appleseed with a Bushnell TRS-25. I don't think ANY 1 power red dot is worth more than the money I paid for it. It consistently gets rave reviews on about every forum, Amazon and Optics Planet. I would never pay $400 for something just as good for under $100.
Quote from: Polaris on February 05, 2014, 05:13:19 PM
Tactical/red dot/AR scopes are generally (there are exceptions) geared towards CQB (and marketing to everybody who wants to fire lots of rounds at big targets and look cool). They are not intended for precision shooting at longer ranges although they may advertise features that sound "long-range."
This is pretty much correct.
A notable exception is the ACOG, which is designed for distance shooting, out to 800 meters.
Then again, an ACOG isn't cheap, not even close.
Most folks simply won't need one, I've got one (TA 31) because I used one (retired from an infantry unit), and sometimes I need to be able to teach it, if I am teaching military folks, especially locally.
Folks here that need good optics should consider using more normal items. They will do all you need to do, and are still reasonably priced.
http://kalinkaoptics.com/rifle-scopes/posp/weaver-dovetail-picatinny/posp-8x42-d-variposp-w-black-finish-five-setting-adjustable-illuminated-reticle-independent-focus-and-1000-meter-rangefinder-rifle-scope-weaver-version.html This is a no-nonsense long range SDMR optic with a reasonable price tag and useful features. Combined with a QD mount and co-witnessed sights on a 6.5 or 7.62 battle rifle, I couldn't think of a better combination. These are made by a former Soviet mil contractor to military specs.
One of their more compact scopes would be appropriate for precision shooting at 5.56 ranges.