Sightron SIII 3.5-10x44MD Riflescope
By Chuck Hawks
The Sightron SIII (Series III) 3.5-10x44MD is a lot of riflescope by almost any measure (size, performance, or price). It is, first of all, physically a large scope with a 30mm main tube and a 44mm objective lens. Its target style adjustment knobs are large for convenient fingertip adjustment and its side mounted focus (parallax correction) knob adds a third knob to its adjustment turret. Its fast focus eyepiece extends the ocular bell assembly, and when you screw-in the (supplied) 3" sunshade, you have a long riflescope. At 24.6 ounces it is no lightweight, either.
Bulk and weight are definite negatives in a riflescope. I mean, you've got to carry the extra ounces in the field, not to mention how the weight affects the balance and handling of your hunting rifle. That is one reason I have generally eschewed scopes with 30mm tubes. Their primary selling point to the consumer is brightness (which may or may not be true, but is easy to sell), while their primary attraction for the scope manufacturer is increased windage and elevation adjustment range (80 MOA in each direction in the case of the SIII).
Sadly, so many new rifles are poorly assembled these days that it is increasingly common to find that a rifle's receiver/barrel are sometimes simply not true, or the scope mount base holes are not straight, or the barrel itself is not straight. And these problems are not confined to any one brand, country of manufacture, or price range. These sloppily manufactured rifles don't shoot where the scope looks and there may not be enough internal adjustment range in a 25mm scope tube to bring the two together. The buyer tends to blame the scope, rather than his new rifle that is actually causing the problem, much to the chagrin of the scope manufacturer.
European scope manufacturers figured this out years ago and have been pushing 30mm main tubes ever since. (Maybe they see more defective and out of alignment rifles?) More recently, the 30mm tube craze has made it to North America, so I decided it was time to get with it and review a 30mm scope.
Being no fool I requested, and duly received, a Sightron SIII 3.5-10x44MD scope for review. I figured that I should make my first foray into the world of 30mm tubes worthwhile. The SIII was nicely packaged and came complete with lens caps, sunshade, a scope wrap, lens cleaning cloth, instructions, and Sightron's excellent Lifetime Replacement Warranty. The latter is worth the paper it's printed on because Sightron's customer service is among the best.
The SIII is made in Japan, long recognized as the land of good optics. And the SIII will only serve to enhance that reputation. Not only is the 3.5-10x44 physically large, it is also an optical giant. And that is a good thing. The view offered by the SIII's fully multi-coated optics is bright and contrasty, and sharp from edge to edge. Optical aberrations seem very well controlled, especially coma. I even did a little night viewing, and while the SIII is not an astronomical telescope, it gathers a lot of light for a riflescope.
The scope's mechanical construction seems sound. It is built on a one-piece main tube. The adjustment turret is substantial and incorporates side focus (the knob on the left) as well as target knobs for elevation (top) and windage (right side). All are fingertip adjustable. All adjustments feel precise and work as advertised. So does the industrial strength, fluted, zoom ring and the knurled eyepiece focus ring, which incorporates a rubber ring to protect eyeglasses on its end. The windage and elevation adjustments click in 1/4 MOA increments, which proved to be accurate in our test scope.
Like other Sightron scopes, the SIII incorporates Sightron's ExacTrac technology. The ExacTrac erector tube incorporates an integral ring for a constant pressure point to keep a constant and perfect point of impact, on or off zero. This insures the accuracy of Sightron scopes under severe use and heavy recoil.
I would suggest that some range markings (in feet or meters) would be nice on the side focus knob. At present there are only unlabeled fine hash marks with an infinity symbol at one end. These are in gold, as are the small magnification numbers on the zoom ring and the Sightron name on a ring around the objective bell. There is a modest "SIII" in gold on the cap of the side focus knob. All in all, this is a restrained looking scope, as befits its high price. If I want to advertise, I can always wear a T-shirt.
The supplied reticle is a mil-dot type. This is essentially a wide Duplex reticle with four little dots strung along each of the thin vertical and horizontal crosswires between the intersection point and the beginning of the heavy part of the reticle.
If I am reading the Sightron Mil-Dot Specification sheet that was supplied with the scope correctly, each dot (D) subtends 1" at 100 yards with the scope set on 8 power, while the fine crosswire (E) subtends 0.2" and the heavy part of the Duplex (C) subtends 1.4". At that distance and magnification the dots are 4.4" apart (B) and the space between the points of the heavy portions of the Duplex crosswire (A) is 45.0". At other magnifications and/or ranges these figures will be different.
According to Barry Marks, who contributed the "Mil-Dot Table" found on the Scopes and Sport Optics Page, the formula for estimating target range is: target size (in yards) x 1000, observed size in mils equals range to target.
Once you figure it out, the mil-dot reticle can be used to estimate range and holdover. A good laser rangefinder, a trajectory table computed for your rifle and load, and a mil-dot table are big assets to getting the most out of a mil-dot reticle.
Frankly, I have never had much use for complicated reticles in the field. I always fear that while I am measuring ranges and calculating trajectories my deer will get tired of waiting and go visit the next hunter. However, the beauty of the Sightron version of the mil-dot reticle is that it is a good reticle even if you choose to ignore the little dots. The heavy part of the Duplex leads the eye naturally to the intersection of the crosshairs, while the fine portion subtends little of the view and gives a precise aiming point. It's a good reticle for a long range hunting rifle and terrific at the shooting range.
Following are the specifications for the Sightron SIII 3.5-10x44MD riflescope.
One advantage of the fat 30mm main tube is that it is better proportioned to a large diameter objective. The 3.5-10x44mm SIII looks and is proportioned about like a 3.5-10x40mm scope built on a 25mm main tube, and requires a similar amount of clearance over a rifle's barrel. Standard low scope rings were all that was required to mount the SIII despite the scope's large objective.
I mounted the SIII on a Weatherby Mark V Deluxe rifle chambered for the .257 Weatherby Magnum cartridge using Leupold bases and Leupold 30mm STD rings. As always, the windage adjustment built into the Leupold base meant that I didn't have to waste any of the scope's internal windage adjustment range aligning the axis of the scope with the axis of the barrel. In fact, when I bore sighted the rig using my Bushnell Magnetic Boresighter, only a couple of clicks of elevation were required.
The following day I was off to the Isaac Walton gun range south of Eugene, Oregon. This outdoor range offers covered bench rests and target stands at 25, 50, 100, and 200 yards. The summer weather was fair with sunny skies and a high temperature of about 80 degrees F. The light wind was not a problem for the .257 Wby.
After verifying that the crosshair was properly focused for my eye, very easy to do using the SIII's fast eyepiece focus, I was ready to begin shooting. Stuffed in my range bag were a couple of boxes of .257 Weatherby factory loads using 120 grain Nosler Partition bullets, the preferred load in this rifle. As always after bore sighting, I started shooting at 25 yards to insure that the first shot would at least hit the paper. I set the SIII's zoom ring at 3.5x (to maximize depth of field) and used the side focus knob to sharpen the image at 25 yards. Surprisingly, the very first bullet I fired punched into the 10 ring of my target. No scope adjustment necessary!
I then moved to 100 yard targets, where I did the rest of my shooting. All groups consisted of 3 shots in order to minimize barrel heating, which is a problem with a Weatherby Magnum, especially in hot weather.
To zero the rifle at 100 yards I set the SIII at its maximum magnification (10x) and readjusted the side focus knob for best visual sharpness. I checked to see that this eliminated parallax, and it did. The intersection of the fine crosshair remained motionless against the target as I moved my head around behind the ocular.
The first couple of groups at 100 yards centered about 1" to the left and 4" above the point of aim, which was the center of a Hoppe's "Crosshair" sighting target. I made the required windage adjustment (4 clicks right) to approximately align the scope in that direction and shot another group to verify that I had done so, while refining my windage adjustment. It's best to make adjustments in one direction at a time.
Then I moved to the elevation knob, since the rifle was still shooting high. To take advantage of the maximum point blank range (+/- 3") of the flat shooting .257 Wby. cartridge, I zero my rifle to hit 2.5" high at 100 yards. This means that I had to bring the group center down about 1.5". I turned the elevation knob 6 clicks in the "down" direction.
The next group centered 2.5" high on my 100 yard target. I was finished zeroing-in my rifle. I had fired a total of exactly 15 shots, and some of those were superfluous. That is how it should be when sighting-in a scoped rifle. Remember that the next time you waste two boxes of ammunition sighting-in a "bargain priced" riflescope.
Everything on Sightron's SIII 3.5-10x44 scope worked perfectly. The target type, fingertip adjustable windage and elevation knobs were accurate and especially easy to use. So were the side focus, eyepiece focus, and zoom rings. The reticle is precise and easy to see. The optics are great and the eye relief is adequate.
Sightron's flagship SIII 3.5-10x44MD riflescope, with a MSRP in excess of $900, is competing with some of the world's best (such as Kahles, Leupold VX-L, and Swarovski AV) for a share of the upscale scope market. Fortunately, its quality and performance easily justify its relatively high price.
Just as with the SI and SII scopes we have reviewed here at Guns and Shooting Online, the Sightron SIII is very competitive in its price class. It seems that you get a lot of riflescope for your money with a Sightron at every price point. For additional information about sightron scopes, visit the Sightron web site: www.sightron.com
Copyright 2007 by Chuck Hawks. All rights reserved.