If possible, check zero the way you hope to shoot game. Changing the type of rest can change your point of impact.

You've traveled far. Airports swallowed your rifle case, then disgorged it with fresh dents and scratches. For the last dozen miles, your rifle has ridden tight in an age-hardened leather scabbard. Tomorrow, you will hunt. But will your rifle hit where you point it?

Checking zero in the field makes sense even if you've not dropped your rifle or had it extensively banged about during travel. Modern scopes and mounts will endure terrific punishment, but a point-of-impact surprise can also result from changes in bedding. If you zeroed in a dry place and are hunting in rain, tight bedding in a walnut stock can pressure the barrel as the wood swells, throwing your shot wide.

Swings in temperature can have an effect too, even with synthetic stocks. Ammunition temperature influences trajectory. And if you must borrow ammo or change loads, you'll want to see where those bullets strike. Also, you may find that the hunting environment affords you little chance to employ a rest or a bipod--the support you used to zero. Shooting from sticks or with a tight sling, you'll likely find a shift in point of impact.

So even if there's no reason to suspect your rifle has suffered a blow, checking zero in the field can improve your chances for a good hit.

The first order of business is to bring some extra cartridges for the task. You'll also want proper targets, because shooting at a can or a rock doesn't tell you enough about bullet placement relative to point of aim. Pack a half-dozen of the paper targets you like best, and a stapler or tape to affix them to a backer.

When you field-check zero, hold the rifle firmly, as if you were shooting at game. Use a sling or a bipod if you expect to use either on the hunt. Even if you have the luxury of a bench, apply the pressures and tensions on the rifle that you most often apply when shooting at game.

Check the placement of the first round from a clean, cold barrel. Firing three shots into a group without marking each one can leave you wondering if that flier was the first shot or the last. Commonly the first round will land outside group center. That's all right, as long as you know it.

Zero for the first shot; it matters most. Let the barrel get cold between groups if you find a warm tube changes bullet impact.

Zero so the midrange trajectory, or the highest point of the bullet's arc above sightline, is no more than three inches. I prefer bullets from most flat-shooting hunting rifles to land two inches high at 100. I can then aim dead on to 200 or even 250, depending on the load.

Don't adjust your scope unless you must. Hunting camp is no place to tweak and tune. A softpoint that lands half an inch left of your aiming point will still kill. On the other hand, shoot enough to establish an average. A single bullet may delight or dismay; neither reaction is warranted. Fire three shots at least.