I'm surprised how many shooters buy riflescopes without knowing how to use them. At a seminar not long ago, I feared my audience would soon grow bored as I reviewed basic scope components and adjustments. Instead, they listened intently. Lots of questions followed. In retrospect, I was wrong to assume the use of a modern riflescope would be intuitive. Here's a quick look at setting up a scope and getting the most from it.
Mounting Your Scope
After affixing the scope to your rifle, you'll next focus the reticle by rotating the eyepiece. On traditional scopes, the ocular housing itself turns on very fine threads and secures with a lock ring. Helical or European-style eyepieces have no lock ring.
Loosen the lock ring and spin the eyepiece (or rotate the helical ring) out until the reticle image is noticeably fuzzy. Point the rifle toward the sky (not toward the sun though) or any neutral background without an object in the field. Don't point at a target, as your eye will automatically try to bring that object into focus. You want your eye relaxed when setting up a scope.
Now turn the eyepiece in until the reticle appears sharp. Lower the rifle, close your eyes, shoulder the rifle to the sky again and open your eyes. The reticle should seem sharp instantly. If it doesn't, tweak and repeat. Give your eye too much time in the sight and it will work to sharpen the reticle, producing a false read.
Scopes of modest magnification deliver an acceptably sharp target image from woods ranges to infinity, and their "zero parallax" range--where the crosswire stays on the target no matter how your head is positioned--is usually 100 or 150 yards.
An adjustable objective lets you boost definition and eliminate parallax error for any distance when setting up a scope. It's most convenient as a third dial on the turret--an increasingly common feature on high-power scopes. The dial lets you adjust from shooting positions. A caveat: Don't use the scale on dial or sleeve as a rangefinder or assume that dialing to a known yardage will give you a tack-sharp image. Not all scales are perfectly marked, and not all eyes are the same.
If your scope has resettable windage and elevation dials, use them. Some allow you to reset "0" to the witness-mark after zeroing simply by lifting the knob, rotating it click-free, then letting it snap back. With others, you can index the knob after loosening a set screw.
While not necessary, indexing to "0" enables you to add elevation by clicking without losing your point of departure. I prefer not to click for windage. I zero in calm conditions and then hold off for wind in the field. However, a resettable dial lets you adjust for wind, then return if you like.
Protect Your Glass
Keep scope lenses clean and protected with caps during transit. I prefer to hunt with uncapped lenses except in constant rain. But modern flip-up caps shield lenses while giving you instant access to naked glass. See-through caps work, too; you can wipe them free of water, snow and dust without fear of scratching. Hydrophobic lens coatings such Bushnell's RainGuard and Zeiss's Lotutec bead and shed water so you can hunt in light rain and snow without caps.
To clean bare lenses, dampen a lens cloth or clean tissue paper with lens-cleaning solution (same as for eyeglasses). Do not spray solution directly on the glass. With soft, circular strokes, wipe the lens from the center out to the rim.
In the field, avoid putting stress on the scope tube. While modern riflescopes are very strong, they weren't designed as handles. Horseback, I scabbard my rifle under my right leg, muzzle angled down and to the front, scope up. If an outfitter straps the scabbard on with the rifle upside down, he loads scope and mount with the rifle's weight and more at every step. A vertical carry ahead of the seat can also stress the scope, as the rifle typically tilts butt-forward.
Letting a rifle bounce on the scope may not bend it or cause it to slip in the rings, but why take a chance? Also, if the horse or mule falls, better that your scope is up than down. Of course, no scabbard position will protect the sight from a roll-over. A horse tumbling down an Alberta mountain once bent my scope's eyepiece tight to the bolt handle, rendering the rifle useless.
When cleaning your rifle, keep oils and solvents off the glass. Alloy tubes need no petro-coating in storage, but a light wipe with an oily or silicone cloth makes sense on steel tubes and rings. A drop of oil or WD-40 in ring-screw recesses helps prevent rust where water often lingers.
Traveling With a Scope
Packing your rifle in a hard case, orient the scope toward the handle so when you carry it, or a baggage handler heaves it, the rifle doesn't jam the scope against the case. Big objective bells, turret-mounted parallax dials and tall elevation knobs can test the dimensions of hard cases. If the scope doesn't fit with room to spare--that is, if there's no cushion between it and the shell--consider removing it and packing it separately.
A friend recently traveled to Africa with three rifles. He removed each scope. Checking zero after re-mounting them on arrival, he found that he didn't have to set up his scopes again.. Modern quick-detach (QD) rings, available from several manufacturers, make this possible and are a smart choice for any traveler--for convenience and to protect the scope.
No matter how confident you are that zero hasn't changed, check by shooting before you hunt.
You're heard people excuse poor marksmanship by blaming the scope. Honestly, in four decades of hunting, I've had only one scope failure that wasn't due to a trail accident or abuse. But I've seen lots of poor shooting and met lots of hunters who got less from their sights than they could have because they didn't know how to adjust or care for them. Taking a few minutes and setting up your scope right can bring big dividends.