A Rational Look at Irrational Glass: Hunting Riflescopes

By Randy Wakeman

There is a strange allure to riflescopes; technical details and real world performance are often ignored for our peculiar ideas of romancing a scope. How often have you heard "I love my xxxx scope?" Naturally, that tells nothing of what a scope does, no more than a meaningless "I bought a xxxx." So far, so what? It tells nothing, compares nothing, and often sounds like we are dating aluminum tubes rather than actually using them.

There are some fundamental areas of agreement that hold up regardless of the name printed on the side of our little aluminum glass holders, fundamental reasons why a riflescope is appropriate for field use. If we can accept what virtually all major scope manufacturers understand, then perhaps a bit of progress can be made. Consensus, of course, is far too much to hope for.

One-piece tubes are superior to two or three piece main tubes. It is not just the extra potential leak paths; anytime you machine threads into an area of a tube, you weaken it as the wall thickness is reduced. Threads have tolerances. If they did not, threaded components could not be hand assembled. From a design standpoint they are inferior in strength, assuming the same metallurgy. There is only one reason multiple piece main tubes exist in scopeland today: they are cheaper to assemble. This is both basic and universally embraced.

Of course, all scopes are built to a price point. A reputable manufacturer may choose to use a multi-piece tube (economizing on tube cost) in order to invest more in another component (better glass or better quality control, for example).

Scopes with "fully multi-coated" lens elements are generally preferred over "multi-coated" or "fully coated." The subject of the type of lens coatings is a complex, and usually proprietary, topic. However, the composition of some multi-coatings is known. Here is one example as cited in a patent:

". . . one particular preferred embodiment includes 70 nanometers of aluminum oxide (Al2O3), 70 nanometers of ZrO3, 225 nanometers of MgF2 and 140 nanometers of SiO2 where it is desired that the wavelength of visible light at 550 nanometers be most clearly and completely transmitted through the lens."

We have come a long way from un-coated lenses, and the single coats of magnesium fluoride that were once as good as it gets, and that's a good thing. Fully multi-coated lenses, if properly computed and precisely applied (another whole topic for consideration), provide reduced flare and maximum light transmission. Understand, however, that a poorly or inappropriately multi-coated lens element can be inferior in service to a lens element with an optimally applied single layer coating. Choosing the most appropriate coating formula(s) for a given scope at a given price point comes down to the judgment and integrity of the scope's manufacturer.

When adjusting a scope, it can be frustrating to turn windage and elevation adjustments only to discover that what the scope does is unpredictable, as if it has a mind of its own. For that reason, accurate internal windage and elevation adjustments are important. The key here is consistency and repeatability. Good design and very precise machining and assembly are more important here than the alleged amount of change indicated by each graduation or click. In fact, very precise machining and assembly are crucial throughout a riflescope, which is why bargain priced scopes are seldom bargains in the long run.

Most hunters are horribly over-scoped. It is easy to name the super-high magnification big game hunting scopes that offer appeal: that would be none of them. Consider that the favored military sniper scope has been the Unertl 10X fixed power. More than 12X magnification causes more problems than it is worth in most situations, and very few big game hunting applications call for more than 6X. Less in most cases, if you happen to believe that Jack O'Connor knew what he was talking about.

Over 6X or so, all the mysterious problems we love to gripe about appear: the field of view shrinks, target acquisition slows, the exit pupil shrinks, eye relief becomes critical, and our scope may go out of focus without the benefit of an adjustable objective. (The latter requires increased expense, size, weight, and complexity and is generally undesirable in a big game hunting scope.) Internal adjustment range tends to decrease with a large increase in potential magnification, and the size and weight of the scope increases, adversely affecting the balance and handling qualities of the rifle. That is a pile of negatives only to get a less forgiving scope with less image quality for the dollar when all is said and done.

There are more important things about a riflescope than brightness, of course. No one could possibly look through a scope and tell you if it is a 90% light transmission scope, or a 93% light transmission scope. No manufacturer could tell you that on an individual scope, either; the values are calculated, not measured from your personal scope.

One of the most important things a scope can do is hold its zero from shot to shot. Having a crisp image of what we are missing is a blessing of limited appeal. The ability to survive the repeated recoil of even the most powerful rifle is another key aspect of any big game hunting riflescope. A scope that falls apart during a hunt does not bag any animals, and even the most liberal dealer exchange warrantee is worthless in the field. The integrity and reputation of the manufacturer is probably your best guide when evaluating the durability of riflescopes.

On the other hand, we all too often are blinded by the commercial magnetism of "branding," and prefer simplistic answers to complex questions. There is no absolute "best," but that won't keep us from asking such a myopic question. We also like to ask if something is "worth it," when obviously any notion of worth and value is a personal impression not neatly categorized. We don't get what we pay for, we never have: we get what we bother to research, investigate, compare and define in terms of our own personal needs and applications.

Unfortunately, some of the nuances of scopes are unlikely be available at all, much less to the level of being reliably compared. Wouldn't you like to know which scopes, of any brand, have the highest return rate from that brand's line? And which brands have the lowest repair rates? Wouldn't you like to know what deviation from scope to scope is considered be within normal tolerances? What level of polish is the minimum allowed on your scope?

With a riflescope often being comprised of some seventy parts, it is not hard to understand that the opportunity exists for a wide spread in performance between products that come in the same box. Quality and quality control are among the least understood, least appreciated, and most expensive aspects of scope manufacture. Once again, the integrity and reputation of the manufacturer is probably your guide to these intangibles.

At one time, "labeling" was considered a damnable paintbrush. It is, of course, convention in the attempted generation of brand loyalty today. Choosy mothers choose "JIF."

We are actually quite fortunate today, as two hundred-dollar bills can buy us build quality, precise machining, and better coatings than were available to the customer at any price fifteen years ago. There is little dispute that a couple of hundred dollars can give us a lot of image quality, durability, and features.

Here are a few scopes and companies (in alphabetical order) with which I have had outstanding experiences in far more demanding applications than creating a hole in a piece of paper. Naturally, the only person you need please is yourself. Hands on comparison, preferably not just in a well-lit retail store, will help you home in on your own preferences. These scopes are worthy of your attention. All represent a good balance of the basic attributes discussed above.

Bushnell Elite 4200 2.5-10 x 40mm: Rigid specifications, produced by Light Optical Works (considered Japan finest OEM facility), light transmission that no one has even claimed to have bettered, a true 4X power range, Bushnell "RainGuard" and an upscale titanium-enhanced tube makes this a scope with which anyone should be pleased. The Bushnell 4200 1.5-6 x 36mm is an equally impressive offering.

Burris Fullfield II 2-7 x 35mm: The latest of the Burris Fullfield line is actually more of a 2-3/16 x 8 power scope based on exit pupil (2.1875 x 7.61) that offers double internal springs, quad ring seals, quick focus, Storm Queen scope covers, and a ballistic reticle to boot. All this offered at a surprisingly low price. The newly designed Burris Signature Select 3-10 x 40mm is an upscale scope that offers image quality I can readily see.

Sightron SII 3-9 x 42mm. This is the scope that defines "Sightron," and a scope that came out just right. Sightron SII scopes are Guns and Shooting Online favorites. I've used a variety of Sightron scopes for some time now. They can take a lot of recoil, exhibit good machining quality, and excellent tracking and their "ExacTrack" adjustment system has proven merit. The internal adjustment of 95 inches is over 50% more than you find in most scopes of this configuration. The 42mm objective offers a large exit pupil, yet the size and weight of this scope is not seriously compromised. I have yet to be disappointed with a Sightron SII scope, and I have torture-tested and hunted with many of them.

With the time, effort, and cost of hunting and shooting these days it has never been easier to find a scope in which you can be confident. These scopes, from three competing companies, all do more in the field than most of us can use. None crack the $400 street price barrier; in fact the Burris Fullfield II is in the $165 range, the Sightron is in the $200 range. You can trust your hunt to any of them. I have.

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Copyright 2006, 2016 by Randy Wakeman. All rights reserved.