IOR 2.5-10x42mm Tactical Scope

09 October 2002
By Scott Powers

IOR telescopic sights have been on the American market for several years now. At the request of their American market they have changed their products to better suit us and continually work to improve the designs. They have adapted several times to meet demands. A good example is the turret adjustments. My first ever experience with an IOR scope was interesting in that the turrets at that time were graduated in Mils. To a hunter and shooter in this country, it seemed pretty odd at the time but I am sure it made sense once you got used to it. However, American shooters are rather entrenched in the idea of adjustments in minutes of angle and in short order the scopes coming from Rumania were calibrated accordingly. Using German glass, they represented a fair product for the price and provided excellent optical clarity for the dollar amount spent. They are still developing their products to meet our demands and in some cases have a small distance to go, but over all, if you want high-end glass in a tuff and usable package, IOR represents one more option on the ever growing market of tactical oriented glass.

After a bit of badgering I finally was loaned three IOR scopes to review for Sniper Country. The first, the topic of this article, is the 2.5-10x42mm Tactical. Outwardly, the scope appears very substantial and this is reflected by its 17 ounce weight. Made of a heavy duty 6061-T6 aluminum alloy, its not overly heavy by any means, but it does feel substantial. To put it into perspective, 17 ounces is about what a Glock 17 weighs so, as you can see, its not a boat-anchor of a scope. It measures roughly 13.5 inches in length and has a 30mm tube. At one time it came in your choice of 1 inch or 30mm but that time has passed. It is now only available in the 30mm diameter which makes sense considering its intended use. In the 42mm objective resides glass by Schott Glasswerk of Germany. More on that later. The scope is nitrogen filled, fog proof, water proof and shock proof (it has a magnum lock!) and a glass-etched reticle.

Internally, the scope provides 88 minutes of angle of adjustment. Using a .308 NATO round, reaching 1000 yards should be no problem when mounted on a flat base. Assuming your rifle zeros at the scope's mechanical zero, you would still have 44 moa of UP clicks to go. Even the old M118 round only needed 41 to 42 moa to reach 1000 yards. Field of view at 100 yards is 34 feet at 2.5x and 11.9 feet at 10x. Exit pupil ranges from 16.8mm at low power to 4.2mm at 10x. Light gathering ability and transfer should not present a problem. I always prefer scopes with 42mm objectives, or less, due to the problems one may encounter when mounting a larger objective. I am certainly biased towards 40mm to 42mm scopes -- if you look in my collection, its all you will find. Headlamps on rifles do not interest me personally. ALL lenses, both internal and external, are fully multi-coated in an anti-reflective coating developed by Carl Zeiss. The T-3 coatings in this case. Judging by what I have seen so far in the yard, this coating works exactly as advertised. Reflection is kept to a minimum and light transfer is excellent.

Enough of the spec sheet data. My initial impression of the scope is one of strength. It appears to be built to last and to take the hard knocks one might dish out in the course of a hunt or tactical shoot. The finish is excellent and on par with other brands in this price category. One can adjust the diopter focus for their eye by rotating a rubber coated ring at the ocular end of the sight. Focusing is easy and only takes a second. A smart shooter will mark the scope body once it its focused to their individual so they can easily return to this setting should someone refocus the ring. The ring won't displace on its own and provides fairly decent resistance to movement. I rather like the feature as one can adjust focus as necessary in the field. This particular scope will eventually be handed over to a friend, who purchased it as soon as he handled it -- so in terms of perception, it's a winner. Only range time will tell, but that is yet to come. On appearance alone this scope rocks. It comes with a very nicely executed screw-in sun shade and heavy duty lens caps which are retained with dual elastic bands of thick rubber. I'd probably zip tie one of these bands to the scope tube and let them hang off the side, ala dummy cord, when the scope is in use. Alternative is to order a set of butler creek flip-up scope caps which will provide the extra advantage/disadvantage of shielding the diopter ring.

The elevation and windage turrets are graduated in 1/2 moa increments. A good feature for a tactical or hunting scope meant to shoot at maximum ranges. More on these later. They are protected by external caps. This is one feature I am not fond of in both American and European scopes. Having turret caps just means something to lose. Give me turrets that require no external cover. This has never stopped me from buying such a scope, but I never understand why so many manufacturers do this. The scope is nitrogen filled and water proof. Adding a cap which seats on a secondary o-ring certainly provides an extra measure of protection for deep water, but ultimately, I end up leaving the caps in my pack or bag anyway.

The turrets are clearly marked in 1/2 moa increments and one full rotation of the turret will net you a 26 moa of adjustment. Put into perspective using a 308 rifle, from your 100 yard zero, one rotation will get you to roughly 760 yards or thereabouts. The clicks are firm and audible. The markings are bright white and easily seen in low light. The top of the turrets are marked with an arrow to indicate UP for elevation and R (right) for windage. I mounted the scope and performed a rough bore sight zero. A word or warning here. This scope's turrets are adjusted in the traditional European manner. There are two screws on top of the turrets which must be loosened, NOT removed! See below for my less than stellar bonehead move of the day. To zero this scope you dial in the turret to your point of impact, loosen the two screws, hold the upper portion of the turret in place and then turn the turret sleeve until you see zero on the dial. You then hold both sleeve and upper ring in place while you tighten the set screws. Its simple enough. But unlike typical American methods. One advantage of this system is that you have infinite adjustment. In other words the inner mechanism of the turret can be moved smoothly in either direction so as to exactly cover your point of impact. Once you tighten the set screws, the system then relies on the clicker for actual incremental adjustment. I am spoiled by traditional American systems and this is one nit that I have on every European scope I have ever handled that uses this method of zero adjustment. On the one hand, its very nice, because you really can dial exactly to point of impact. On a traditional American scope, you might only get within an 1/8th or worse, 1/4 moa. However, being a former straight leg, and not particularly bright, I naturally removed both of the set screws BEFORE reading the directions. Bad move. The internal drum drops down and the provided set screws are NOT going to reach it to bring it back up. READ THE DIRECTIONS folks. Let me be the moron who experiments for you. This little faux pax resulted in a quick hop to the hardware store for a longer screw, which I used to bring the internal drum back up into position where I could then use the provided -- and not to be removed -- set screws. Lesson learned and no harm done. Read the instructions first and don't assume!

The Reticle is etched on a glass plate. Major plus on the hard core end of the spectrum! No wires to break. Very precise location of each mil-increment. Yes, this is a "mil-dot" scope, or more accurately, a derivative of the mil-dot system. Instead of dots, the reticle, called an MP-8, has hash marks at one mil increment instead of footballs or dots. From the center of the crosshair, you have five major mil increments just like a traditional mil ranging scope. The gap between the heavy outer wire is 10 mils, also like what you are used to. In a twist of individuality, IOR dispenses with the lower heavy post and carries the 1 mil increments down. From the upper vertical heavy bar to the lowest mil tick is 15 mils. This certainly could be useful for hold-overs, large targets and other ranging sessions where you may need more area below the traditional 10 mil heavy post gap. Theoretically, this reticle should make ranging using the mil-system easy since it also provides additional, but not overly cluttered, ticks for 1/2 mils. In other words, between the larger 1 mil tick you have a smaller tick and the gap between represents a half mil. The height of these smaller ticks can also be used to range as they are 1/4 mil tall or wide depending on perspective. Finally, on the vertical line, there are two 10 mil lines oriented horizontally. If this all sounds a bit confusing look at the illustration. Its like any ranging reticle based on the mil system, only with a few additional twists.

In use, the outer posts stand out very well again dark background. Low-light close-range shooting using the outer post is as usual. Center the target in the gap and fire. The fine inner wire is very precise but will, as expected, disappear in very low light. Both inner and outer wires stand out well against vegetation. The inner wire is fairly fine. It stands out well and yet has the advantage of not obscuring the target by being so thick as to make it hard to center up. For those needing full round the clock use of the reticle, IOR also offers an illuminated version of this scope. The non-illuminated version can only use 10x for ranging using the normal methods. The illuminated version has the reticle located to allow you to range at all magnification settings. The reticle grows or shrinks as you zoom up or down, maintaining the mil-relationship. I'll be honest here, I can never remember if that means its on the first or second focal plane. I can tell you however, that the illuminated version takes a standard Duracell 2032 battery. According to the literature, the non-illuminated scope can be had with a standard mil-dot reticle in addition to the MP-8.

The glass? Well, the glass is simply top notch. Crisp and distortion free right to the edge with little hint of darkening. Tested against my Zeiss Test Pattern at 10 meters and set at a magnification of 4, I was able to resolve down to 6.3 on the pattern. I could almost make 8 but not quite. There is no way to fine focus the pattern at 10x at so close a range as 30 feet, so I had to go with the highest magnification on which I could get a fine focus, which was 4x. I saw no glaring signs of astigmatism or spherical aberration. Contrast was excellent as was clarity. Color was accurate and bright in all uses both out of doors and inside. At the range, the reticle stood out very well against my targets and unlike my Bausch & Lomb varmint scope, did not hide my small aim points. Its not a hairline reticle, but it is gratifyingly thin.

Range time. With the versatility that a variable affords, this scope is just as likely to be mounted on a hunting rifle as well as a tactical rifle so I decided to mount it to my .308 caliber Remington 700 BDL for the test. This particular rifle is fairly accurate and able to shoot just under moa. Since I was testing the IOR scope I also figured I might as well test the IOR tactical rings and bases at the same time. With the zeroing chores done, I proceeded to shoot a "box" to test the tracking. I decided on a 5 moa adjustment for each circuit since I only brought 8.5x11 inch targets. Setting up at 100 yards and using the same point of aim for all shots fired, I fired 20 rounds in a round robin chase. For those of you not familiar with this test, it involves firing one round, adjusting elevation UP the specified amount (5 moa in this case), firing a round, adjusting the windage RIGHT the specified amount, firing another round, adjusting the elevation DOWN the specified amount, firing again and finally adjusting LEFT the specified amount, which should bring you back to the first point of impact. "Rinse an Repeat" until you have drawn a square of bullet holes in the target. It's a fairly good indicator of a scope's ability to repeat. In the case of the IOR 2.5-10x42 tracking was consistent but one anomaly appeared. As I said, I used 5 moa increments. Measuring the center of each cluster it would appear that the scope adjusted right at 4.5 moa. In other words, the mean center of one group cluster was 4.5" from the next group. This is not the first time I have seen this in a scope -- in fact just about every scope I have ever tested seems to exhibit something like this to some extent. There were no glaring wild shots and for some reason, the fourth cluster, the lower right hand one, was impressively tight at .473 inches. The other three groups maintained a more normal .8 inch average. Go figure. Maybe by the time I got to the bottom of the box I was taking more time to aim. I have to admit, having not been to the range in a YEAR, my OWN consistency is a bit off. The scope performed fairly well but I did notice a slight lopsidedness to the box. The right side impacts were about a 1/4" lower than the left side groups. I would say this was a function of the scope since it was consistent for the both upper and lower right side group. When I'd return back to the zero windage, zero elevation setting that group would come back up 1/4 inch and cluster exactly as expected.

Overall I am fairly impressed with the scope. In spite of the 1/4 moa variance in elevation between the left and right hand groups it was able to repeat well and working with glass this clear is always nice. All four groups were consistently centered with no obvious flyers caused by an internal shift. Once I got used to the method of resetting the zero on the turrets that too became an easy chore. That's all I had time for. Once Keith gets the scope on his rifle and starts shooting at longer ranges I hope to follow up and see how the 2.5-10x42 hold up all the way out to 600 yards, the longest range around here.


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