"Not by a long shot" used to mean bad odds for a gambler trying to fill an inside straight in five-card stud. Nonetheless, nearly every hunting catalog and magazine we look at these days bombards us with "long-range" ammunition, "long-range" optics, and "long-range" rifles.
For most whitetail hunting situations in the eastern half of the country, "long-range" is pretty short. But consider this: One of the most common land units in rural America is a 40-acre field. And there is scarcely a whitetail rifle hunter living who hasn't at least once in his life been sitting in a ground blind or tree stand along one edge of a 40-acre field and seen a buck of his dreams feeding placidly at the fencerow on the opposite side.
How far away is that deer? Just a quarter of a mile, or 440 yards to be exact. Should you try that shot? Probably not. But the temptation can sometimes be overwhelming. Not to mention the growing amount of whitetail hunting occurring in the more open states of the Great Plains and West.
If you're preparing for a whitetail hunt in which a truly long-range shot may present itself, you first need an ammunition/rifle/optics system capable of precise and consistent long-range bullet delivery. The most important ammunition consideration is sufficient downrange energy. Even if your rifle can deliver pinpoint accuracy at long range, it won't do you any good unless its cartridge delivers enough energy to let its bullet perform as designed once it gets there.
I use the "100-yard equality" principle. For whitetails, I take the classic .30-30 as my reference point. A typical 150-grain .30-30 load delivers about 1300 ft/lbs of energy at 100 yards, which is universally considered adequate for whitetails. A typical 150-grain .30-06 load delivers 1300 ft/lbs at about 450 yards. A typical 150-grain .308 Winchester falls below 1300 ft/lbs at around 425 yards. Do the math. A .308 is marginal across that 40-acre field, a .30-06 is OK ballistically, and your .30-30 is not.
Even if you have a truly capable long-range ammunition/rifle/optics system in hand, the weak link is still you. You have to know you can do it. That means you need to actually practice with your system at long-range targets, not just sight it in at 100 yards and rely on what a printed ballistics chart says it will do farther out. The minimum range for proving whether your system will deliver at long range is 300 yards.
I have fired many gun/load combinations that hold sub-MOA 100-yard groups but fall apart by the time they get out to 300 yards, and subtle instabilities in the bullet's flight send it veering off. On the other hand, if a bullet retains its performance to 300 yards, it will have proven its stability, and you can nearly always count on it to continue true as far as it can fly.
If you don't have any 300-yard distance where you can shoot near home, you must absolutely check it out once you get to your open-country hunting fields before ever attempting a long shot on live game. Practice like you'll shoot in the field: resting in a stand or against a tree or a fencepost, prone over your hunting pack, or from your shooting sticks, if that's what you use.
Do not try an extreme-range hunting shot unless you already know you can hit consistently at that distance. How accurate is enough? For whitetails, I use the "basketball rule." A basketball is about nine inches in diameter, so if my rifle/load combination can hit a basketball at any distance, I know it can nail the kill zone of any whitetail I see, from here to there. The bottom line is simply this: If you can't hit that basketball every time at any distance you think you might want to shoot, don't try a hunting shot at that distance.
The second part of long-range preparation is plotting the trajectory for your own individual gun and load. Your zero distance can be keyed to the most likely shots, but if you are going to be ready for longer distances you must also have drop figures firmly established as far out as you are willing to shoot. Published ballistic charts and a wide variety of computer software programs will give you very precise decimal-place trajectory figures. Don't believe them. They are based on the "nominal" performance specifications of standardized formulas from standardized ballistic test barrels. The actual trajectory profile of your bullet from your gun depends entirely on its individual characteristics and its actual velocities, and may be stunningly different from "nominal."
After you've zeroed at your chosen distance, check the actual trajectory at different intervals from 100 yards to as far out as available. Become familiar with the range-compensation features of your scope at the different distances. The only truly reliable procedure is to shoot as many different distances as possible all the way out to your self-imposed maximum range and tape the resulting profile to the butt of your gun. The only way to know what you're shooting is to shoot. And shoot. And shoot.
Finally, don't fight the environment. Rainy days, forget it. If the wind is gusting or variable, don't shoot. Wind is the absolute worst enemy of long-range shooting, and learning to read wind is a lifetime endeavor. Maybe, if you've got five or more years' experience as a regular 600-yard NRA High-Power rifle match competitor, and you constantly practice under windy conditions, you might have enough wind savvy to try a 400-yard shot with a light breeze blowing. Maybe. But if you're just an ordinary hunter, even if you've conscientiously applied every other technique discussed here, don't try a true extreme-range shot on game except when the wind is absolutely minimal.
Don't believe me? Then go out to your home range on a gusty day and shoot at the farthest available targets. If you can't make an on-command long shot in the wind on the range, you surely won't be able to make one in the field.
If you're not willing to take this time and effort, and be sure of what you're doing, you're not really serious about taking a long-range whitetail. You shouldn't try it. No matter what the catalogs advertise. Not by a long shot!