The Rangefinder Revolution
December 14, 2017
Believe it or not, there was a time not so long ago when knowledge of distance was the primary limitation to long-range field shooting. In fact, for the first 30 years of my hunting career, we judged distance by guesstimation. NATO and many of the world's militaries standardized the mil-dot system in the 1950s, which can be used to calculate estimated range, and some sporting reticles can be used through making associated size comparisons. Mostly, however, we used the "football field" method. Most American hunters know what a 100-yard football field looks like, so it was easy to try and guess how many football fields fit between you and the target? This was never precise, but it had one huge benefit. Unless you bothered to pace it off, a shot was exactly as far as you said it was, and nobody could question you. So, when I read older accounts of 500-yard shots (many from the pre-scope era), I factor in blue sky and accept that some of the longer shots of my youth probably weren't quite as far as I thought they were.
Ancient History Although long-range shooting is all the rage today, it's hardly a new concept. Many 1,000-yard matches predate self-contained metallic cartridges and smokeless powder. The accuracy was there, and if you know the range, trajectory is just a number. Known-distance (KD) ranges are one thing, field shooting is another. From the Civil War through Vietnam, long-range sniping was often accomplished by reading distance garnered from map coordinates. There are wonderful stories from the Spanish-American War of our sharpshooters (often still armed with trapdoor Springfields) "registering" their fire on likely target areas just like artillery. This doesn't work well in hunting situations. (How many of us have accurate maps for our favorite hunting locals? I don't.)
Thanks to sporting cartridge velocities (and thus trajectories) that haven't changed much since the 1940s, and game animals still presenting a fairly large target area, we have consistent information at the ready. However, on uneven terrain, it can be difficult to gauge the range difference between three and four football fields. In my youth, 400 yards was considered a very long shot, but with flat-shooting cartridges and lots of practice, this distance was very much in reach. For me, 400 yards is still a long poke, but it's a whole lot easier if I can determine the exact range.
In World War I, optical rangefinders started to change the game for artillery spotters. Initially they were large, cumbersome affairs; no problem for trench warfare. By World War II, the optical rangefinders emerged into two types: coincidence, with one eyepiece; and stereoscopic, with two eyepieces. In both cases, two images were merged into one, so we also call them "split-image rangefinders."
Ranging Inc. in the 1970s hit the market with the first easily portable split-image rangefinders for sporting use. Short-range versions for bowhunters and longer-range variants for rifle hunters. To calculate range to a target, you would look through a viewfinder and, literally, see two images of the object you were ranging. While looking at the target, you would move a sliding scale until the two images merged into one, and read the range! After proper calibration, the rangefinders were accurate at least to moderate range, just not fast to use. I tried them on the range and carried one in the field several times, but I gotta be really honest, I don't recall ever actually ranging a game animal with one.
The first laser rangefinder I saw in the field was Russian military surplus, just after the Iron Curtain fell. Wielded and (thank God) carried by Barnes Bullets' Randy Brooks, it was about the size of a full GI ammunition can. We used it on an elk hunt about 25 years ago. It would range hills at 30 kilometers, but fortunately we didn't find a lot of elk that needed ranging. Turns out that it was not an eye-safe laser! Those things weren't on the market for very long, but I heard stories about cattle being blinded by people ranging a herd.
This was rapidly emerging technology. The first compact laser rangefinder I ever used in the field was from Bushnell, a pioneer in the field and still a leader. I think it was 1994 and I was guiding veteran public relations wizard Kevin Howard in eastern Colorado where we spotted a really odd-looking buck. It was probably a mule deer/whitetail hybrid on a low knoll. Howard handed me this new little gizmo. The buck was about 400 yards (a doable shot), but we had a strong wind and too much brush to allow a low, steady position. So, we started crawling, sagebrush to sagebrush. Every now and then I'd take a peek with that rangefinder to see how we were doing. We were at 235 yards when he made the shot. We didn't do the DNA testing, but I'm still convinced that buck was a rare hybrid. Whatever it was, I fell in love with laser rangefinder technology and have rarely been without one since.
How do they work? The laser rangefinders operate by sending out a laser pulse in a narrow beam, and then capturing the time required for the pulse to reflect back from an object to the sending unit. Using the known speed of light, it calculates and produces the distance on a display. That's pretty sophisticated stuff for a hand-held unit costing less than many riflescopes.
Laser pulses are divided into classes based on strength of beam. Commercial rangefinders (whether for foresters, golfers, hunters, etc.) use the weakest lasers, Class 1 or maximum Class 2. These are regarded as "eye-safe lasers." They will not blind animals but it's still a bad idea to look directly into a laser rangefinder. Military devices often use more powerful lasers, which are not eye-safe but have much greater range. Still, our rangefinders have amazing capability considering their size and price.
Most major optics manufacturers now offer laser rangefinders, and many offer "grades" depending on ranging limits, and thus pricing. Bowhunters obviously need short-range precision; long-range rifleshooters require a lot more range. They will pay more for the capability, but there are plenty of inexpensive, compact laser rangefinders that are rated to 1,000 or 1,200 yards. Despite the rating, actual ranging capability in the field depends on light, atmospheric conditions, the size and reflective quality of the object, and the user's ability to hold a device still enough to get the laser on a specific target.
An interesting fact is that today's digital rangefinder doesn't run out of numbers, it just runs out of beam strength. So, even with inexpensive rangefinders — under ideal conditions — I've ranged large, highly reflective surfaces like a cliff face at far greater distance than the device was actually rated for! On the other hand, under actual field conditions, there have been many more instances where I've been unable to get the range on animals or objects well within the device's capability.
With laser rangefinders, at least to a degree, Boddington's First Law of Optics applies: "You get what you pay for."
Premium-quality rangefinders from premium-quality manufacturers are not necessarily more accurate. But they will (usually) enable faster ranging of smaller objects at longer distances. However, there will be situations where you just can't read the range.
How to use one. It's sort of like flying an airplane, you have to learn to trust your instruments. Start at the range, ranging known distances so you verify the unit's accuracy. Come to trust it, and learn to employ it quickly. In the field, practice with it so you learn the degree of steadiness required and the size of object required to reliably obtain a reading. Remember: Necessary target size increases with distance. I often find myself ranging trees and rocks next to an animal rather than ranging the actual animal, especially when I'm excited.
In long-range situations, precision is increasingly necessary. Serious long-range shooters need the best rangefinders and often mount them on tripods, allowing steady ranging of smaller objects. It's extremely important to be absolutely certain that you are reading the range to the actual target, not intervening vegetation or a highly reflective object just beyond.
Understand, too, that there will be situations when you can't get a reading or you simply don't have time. In preparation for such circumstances, I suggest using your laser rangefinder constantly. When I get on an unfamiliar stand or in a likely position where an animal might wander by, I range everything in sight over and over again until I have memorized the distances to prominent landmarks. I often play a guessing game with myself when glassing. Using the good old football field method from my Boy Scout days, I mentally estimate the distance to an object. Then I check with the rangefinder and see how close I came. Do this over and over, and you'll be amazed at how much better you will get at estimating distance by eye. Although an essential skill, range estimation by eye is really only practical out to medium ranges. If you're into serious long-range shooting then, on game animals, you simply must know the range. If, for whatever reason, your rangefinder can't tell you, then you're in an ethical no-shot situation.
Capabilities continue to expand. Shooters have long agonized over how to compensate for uphill/downhill angles. Usually this is beating a dead horse; the angle has to be very steep — or the distance very long — before angles make a significant difference. But in long-range shooting everything matters.
I think Leupold's True Ballistic Range (TBR) was the first to read the angle and spit out the corrected distance. This feature is now available from multiple companies. This is another situation where constant casual use of the rangefinder will teach you some lessons, like angles in nature are usually not as steep as they appear. You need some combination of extreme angle, extreme distance, or extremely arcing trajectory before you need to obsess over angles — but when these occur, you better pay attention.
Also emerging are in-scope laser rangefinders that are increasingly linked to in-scope trajectory compensation. I think Swarovski was first with an in-scope laser rangefinder, a very accurate but initially large and costly device. The laser riflescope is still not in extremely common use and not offered by many manufacturers, but it's come a long way.
Last year, I tried out a Burris Eliminator III with huge capability at a (relatively) low cost. Calibration was a simple matter of reading the directions. I quickly took it to 900 yards using the in-scope trajectory compensation. Burris' Eliminator III LaserScope has a 1,200-yard capability.
One important note: The rangefinder can (usually) tell you how far, and some can figure the angles, but none can tell you whether you should or should not shoot. Some readings, farther than you'd guessed, will send a clear message that you'd better get closer. But knowing the range, though a huge benefit, solves just one variable. You still must get steady enough, read the wind correctly, and know your rifle and load well enough to make an ethical shot.
One tool or two? One of the major decisions that every user must make is whether to have the rangefinder incorporated into a binocular or riflescope or whether ranging should be the job of a separate device. There are pros and cons.
Leica's original Geovid was the first top-quality binocular with an internal (and equally top-quality) laser rangefinder. It was a bulky, heavy device, but I found it so handy that I carried it on all manner of serious mountain hunts. The binocular/rangefinder combination will usually be costlier than the two devices separately, and will always be a bit heavier. Current Geovids and newer rangefinding binoculars from other manufacturers are much less bulky than before. In recent years, I've carried a Zeiss 10x45 RF a great deal. It's a wonderful tool, but still a fair amount heavier than a 10x42 binocular.
Having the two-in-one tool is really marvelous, and for sure it makes playing my guessing game a whole lot simpler. You can do it while glassing without changing tools. However, there is a tradeoff. A binocular with rangefinder can be really good, but it is an impossible engineering task for it to be as optically perfect or transfer as much light as a stand-alone binocular of similar quality. Can you see the difference? In most cases, probably not; but it does exist.
Also, it depends on how you hunt. I try to never let go of my binocular. If I'm hunting with a buddy or guide, it can be really helpful to hand off a compact rangefinder and let my partner call the range. Honestly, I use both options. If you're carrying both tools — binocular and compact rangefinder — then you have to switch back and forth, but you can carry lighter and more compact binoculars. Today's compact rangefinder weighs almost nothing. It is, however, extremely handy to have both tools in one. In a guiding role, a rangefinding binocular is essential.
Limitations Stability, size of target, clear path to target, atmospherics, and reflective nature of the target dictate how far you can actually get a reading. Some of these can be mitigated by taking a steady rest with the rangefinder (or putting it on a tripod) or ranging a larger object near the target. For instance, it's extremely difficult to get any rangefinder to read on a prairie dog, but you can usually range its mound.
One significant limitation that you cannot beat is weather. In precipitation or fog, the beam will not penetrate. You will not get a reading. One morning, in the Oklahoma sand hills, I sat in a blanket of fog for an hour. When it started to lift, a nice buck stepped out of the mist on the next ridge. Though far, he wasn't too far, but I couldn't get a reading. I guesstimated 350 yards, held accordingly, and he came tumbling down the hill. Another time, in Alaska during a horizontal blizzard, I had an awesome grizzly on a moose kill, surely within range, but at a totally unknown distance. I still don't know how far it was, but I held for 250 yards and we got the bear.
The laser rangefinder can help you get better at range estimation, so let it teach you. Just keep in mind that there will be times when it can't help at all.