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Are You Using Too Much Scope?

Are You Using Too Much Scope?

High-magnification glass can be more of a hindrance than a help in deer hunting.

By Clair Rees

Winter was setting in along the Utah-Colorado border. It was two days before Thanksgiving, and I was slogging slowly through a foot of snow blanketing the Dolores Triangle. I’d drawn a late-season permit for the area. Hunting had been spotty here during Utah’s 10-day October deer season, when only “so-so” bucks were in residence. I was after one of the mossyhorns that descended from Colorado’s high plateaus to winter in the Triangle when the weather turned foul.

It was snowing lightly when I left the tent that morning. Less than an hour later, I was bucking a real blizzard. Hoping the snow would let up before long, I sat with my back against a large sagebrush that blocked the wind, and settled in to wait.

The blizzard eventually petered out, and only a few scattered flakes still drifted from the sky. Before getting to my feet to shake the snow from my coat and pants, I carefully looked around. A flicker of movement caught my eye, so I raised my binocular for a closer look. Like me, four mule deer had bedded down to wait out the storm — and one was a huge 8-pointer!

I’d spotted the buck as he rose from his snowy bed. Now he stood stiff-legged, looking in my direction. There was no time to waste. I raised my .308 Sako carbine, aimed and shot the deer from where I sat. The buck fell back in his bed as the other deer took flight.

My Sako wore a 1.5-4.5x Bushnell scope. I habitually carried the rifle with the scope at its lowest setting in case I spooked a deer at close range and had to take a running shot. At 1.5x, the scope offered an exceptionally wide field of view. What’s more, I could track and aim with both eyes open.

I didn’t even think about cranking up the magnification. The rifle was sighted-in to print 2 inches high at 100 yards, so I just dabbed the crosshairs behind the buck’s shoulder and squeezed the trigger. The animal fell 256 long strides away — call it 230 yards.

This demonstrated a truism I learned long ago. Shot placement, not image magnification, is the critical factor in taking game. If I can use a 1 1/2x scope to cleanly drop deer more than 200 yards away, do I really need a monster variable that tops out at 14, 16 or even 18x?

High-magnification scopes sporting large 50mm or 56mm objectives were originally designed for beanfield shooters — hunters who sit in an elevated blind overlooking cultivated fields or a power line right of way. Oversized scopes with Mount Palomar optics are fine on a heavy-barreled magnum steadied by a sturdy rest. Weight and bulk aren’t limiting factors when you walk only a handful of yards to climb a Texas tower.

If rifle and shooter are capable of killing deer cleanly a quarter-mile away, an 18x scope may be exactly what you need. This is an exercise in long-range marksmanship rather than careful spotting and stalking.

I was surprised when conventional “walk and stalk” hunters began buying the same kind of scopes. Like engine displacement in cars, American males (and some females) appear similarly addicted to riflescope horsepower.

Are You Using Too Much Scope?That kind of horsepower won’t put more venison in your freezer. Overscoping your rifle can have exactly the opposite result. Here are some pros and cons to consider when scoping your next hunting rifle.

When you opt for a big 4-16x50mm variable, you’re looking at some serious tradeoffs. You can magnify a deer’s image 16 times, but that image will be a lot dimmer than you’d get with an 8x scope. At 16x, a scope with a 50mm objective has an exit pupil 3.13mm in diameter. At the 8x setting, this doubles to 6.25mm. A 3mm exit pupil is adequate in strong daylight, but when it’s cloudy or you’re shooting in early morning or evening light, you won’t see a bright, crisp image. At 8x, exit-pupil size doubles to 6.25mm, providing plenty of aiming light early and late in the day. European sportsmen, who often hunt in near-black conditions, favor large 8x56mm optics. These scopes deliver 7mm exit pupils — the largest a human eye can effectively use.

There’s also the problem of finding your target in the reticle. At 16x, the viewing field  measures only 7 feet across at 100 yards. At 4x, the field of view is more than three times larger (26 feet). If you’re shooting a hard-kicking magnum, be aware that eye relief is slightly reduced as magnification goes up. Crowd the eyepiece, and you could wind up with a “shooter’s eyebrow.”

Size and heft? A 4-16x50mm variable can weigh a pound and a half (or more) and measure 16 inches in length. That big objective lens requires the scope to be mounted high over the receiver. You’ll need to raise your head slightly to see through the reticle, and the scope will be more vulnerable to accidental damage. High-riding scopes also foul up published ballistics tables, which are typically calculated for scopes mounted 1.5 inches above the bore.

My first riflescope was a 4x Weaver. Before I could afford to buy it, I got along just fine with aftermarket aperture sights. Peep sights offered no magnification, but could be deadly on deer out to 250 yards. The 4x Weaver gave a clearer view of my target (which has become increasingly important to aging eyes) and allowed me to place my shots with greater precision.

The next half-dozen scopes I bought were 1-4x or 1.5-4.5x variables. I didn’t need more than 4x magnification for the 100- to 200-yard shots I usually took, and I liked the roomy field of view the 1.5x setting provided.

For many years now, the 3-9x variable has been the most popular scope hunters buy. There’s good reason for this. The 3x setting offers a reasonably large field of view for close, running shots, while 9x is plenty of magnification for shooting deer or elk at 300 yards. I still like 1.5-4.5x variables, but I’ve become a grudging convert to 3-9x variables. 

Most 3-9x variables sport 40mm objective lenses, although 33 to 50mm objectives are available on certain models. It’s hard to go wrong with these proven, no-nonsense workhorses. Reasonable size and weight, combined with a good, useful magnification range, make them the first choice of many deer and elk hunters.

Nikon’s excellent 3-9x40mm Monarch scope can be had with a BDC (bullet drop compensating) reticle. That eliminates guesswork when shots are long, provided you first verify the distance with a laser rangefinder. Leupold, Kahles, Burris and others offer their own range-compensating reticles, and most are available in 3-9x scopes.

While 3-9x scopes remain on top, some shooters are beginning to choose slightly more powerful 2.5- or 3.5-10x models. These scopes may be only slightly larger, depending on objective lens size. At 10x magnification, Nikon’s 2.5-10x56mm Monarch Gold offers a large 5.7mm exit pupil for low-light situations. This scope must be mounted higher than one with a 40 or 42mm objective, but if you want an extra-bright reticle, that’s one of the trade-offs. A scope that size looks out of place on compact bolt action carbines. It also ruins the lightweight balance these rifles have. Leupold, Burris, Vortex and others produce compact scopes designed for short-action carbines. These include trim 2-7x and 3-9x models with 28 through 33mm objectives.

Again, there’s a tradeoff. Compact scopes offer slightly less performance than full-sized scopes. The difference may not be all that noticeable, particularly on a sunny day, but it’s there.

At the other end of the size scale, some scopes boast European-style 30mm tubes. These scopes are necessarily bulkier and heavier than American-style 1-inch scopes, limiting their practical use to full-sized rifles, usually magnums.

What advantages do 30mm scopes offer? That oversized main tube can house larger optics, which theoretically boosts performance. I say “theoretically” because some 30mm scopes sport virtually the same lenses and erector systems you’ll find in conventional 1-inch scopes. When you shell out extra for a 30mm scope, you may not be getting the larger internal optics you expected. This means that 30mm scope may not provide brighter, sharper viewing than your old 1-inch scope delivers. Objective lens diameter is a more reliable indicator of image brightness.

Another reason to buy a 30mm scope is to get a considerably greater range of windage and elevation adjustments. This can be a real plus when you run out of adjustment while sighting in a rifle. It’s possible for scope mounts — even receivers — to be slightly out of true. If this happens, having extra adjustment clicks on tap can be a lifesaver.

Again, not all scopes sporting 30mm tubes have those extra clicks available. Be sure you get what you pay for.

Subscribe Today!Here’s another surprise. I’ve mounted a few 1-4x scopes with 30mm tubes on dangerous-game rifles, assuming they’d be more durable. The fact is, big, heavy scopes are more likely to fall apart under big bore magnum battering than lighter scopes of the same magnification. A heavy scope has more built-in inertia, so it’s more affected by recoil. In addition, that same inertia makes hefty scopes more apt to shift forward in their rings when you fire that hard-kicking rifle. The only cure I’ve found with some 30mm scopes is to lap the inside of the rings for a snug metal-to-metal fit, apply lots of Loc-Tite to the screws, and then fasten everything down tight.

This doesn’t apply solely to 30mm scopes. The heavier your rifle recoils, the smaller (and lighter) your scope should be. My 5 3/4-pound Rifles Inc. .375 H&H Magnum “big bear” rifle wears a 1.5-5x20mm Leupold Vari-X III. This rugged scope weighs just 9.5 ounces, and at 1.5x delivers a comfortingly wide 66 feet field of view at 100 yards. Following the same rule, I’ve mounted a 1-4x30mm Docter Optic scope on a Savage .338 magnum. The .338 generates less recoil than the .375, so the heavier Docter Optic scope was a logical choice.

Large high-power scopes have their uses, but mounting oversized optics on a deer rifle you’ll carry all day is something you may regret.

Reprinted from the September 2007 issue of Buckmasters GunHunter Magazine. Subscribe today to have GunHunter delivered to your home.

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