The days when big game hunters had to rely entirely on dead reckoning to determine the distance to a trophy bull elk are long gone. Affordable laser rangefinders have taken much of the guesswork out of one of the most critical judgments a hunter needs to make.
A laser rangefinder can help hunters sight-in their rifles, calculate the distance to prominent landmarks that are visible from a hunting stand and confirm the distance to a target.
Longtime Steamboat Springs hunter Bill McKelvie said his Bushnell rangefinder is the first piece of equipment he turns to whenever he sets up in a new area for a stationary hunt.
"As soon as I sit down in a spot, I get out my rangefinder," McKelvie said. "I'll pick out a clump of trees and find it's 300 yards away and a big rock and find out it's 400 yards away."
Before any elk come into view, McKelvie already has established in his mind valuable information that will let him quickly assess whether his trophy is in range.
Laser rangefinders made by well-established optical manufacturers such as Nikon, Tasco, Leica and Bushnell cost $170 to almost $3,000. They work by calculating the time it takes for a pulse of infrared light to travel from the device to the target and back. It's a different technology from surveying instruments, which take wavelengths of light into account.
Generally speaking, the narrower the beam of light emitted by rangefinders, the more accurate they are in bright light and hazy conditions. Hunters will pay a premium for the narrowest laser beams.
The first thing a rangefinder does is help a hunter make ethical decisions about whether to take a shot.
"You might see what appears to be a big trophy bull and think it's at 400 yards and be tempted to take a shot," McKelvie said. "Then you get out your rangefinder and find out it's actually at 600 or 700 yards. You realize you'd better not take that shot."
Effective use of a rangefinder begins before the hunter goes into the field. Hunters go to the rifle range and select a distance at which to sight-in so they can adjust their scopes to account for gravity.
They make decisions based on factors such as terrain rifle type, bullet trajectory and comfort level with their own marksmanship.
Judgment still comes into play. It's rare that a bull enters a clearing at precisely the distance a hunter has set his sights in the rangefinder. But when a hunter has used a precision optical device to gauge the distance to the edge of the trees and can quickly confirm target range, he or she is much better informed when deciding to set the crosshairs 3 inches above or below the kill zone.
The need for a hunter to determine accurately the range of a target has its basis in Newtonian physics and an understanding of gravity. Bullets travel at a rate of speed the human eye struggles to detect. But Newton proved that no matter how high the velocity of a projectile, gravity exerts the same force on it as if it were dropped motionless. That means a bullet is falling toward the ground from the moment it leaves the barrel.