• Leupold RX-800i/TBR Laser Rangefinder

    Visually estimating the range to your target is probably one of the most difficult elements of long-range marksmanship to master. You can have the best rifle available, finely tuned hand-loaded ammunition, perfect trigger control and you can memorize the ballistic and atmospheric tables for your favorite hand-load, but you will never be a true marksman if you don’t know the approximate range to your target. Laser rangefinders like the Leupold RX-800i/TBR with DNA technology make the challenging task of ranging a whole lot easier.

    This past fall Leupold provided me with one of their RX-800i/TBR rangefinders for evaluation. This is only my second experience with a laser rangefinder so I still consider myself a novice when it comes to such things, but I’ve used it in both foul and good weather to setup remote shooting locations and range the distance to a multitude of natural landmarks from the corner of the barn on my friend’s farm. (The corner of this barn is the usual location from which ‘shots of opportunity’ are taken at coyotes and groundhogs by the landowner.)

    The Leupold RX-800i/TBR is a 6x23mm monocular with an integrated 800-yard laser rangefinder. In addition to the simple range finding function, the RX-800i/TBR also performs a slew of trigonometric and ballistic functions which can be extensively customized via the menu system to compensate for your cartridge ballistics and/or the declination angle of the shot.

    Basic use of the RX-800i is controlled by a single on/off button, and it couldn’t be any easier - simply point it at the target, push the button and put the reticle on the target. There are several different reticules to choose from, but they are all variants on the crosshair and quadrant lines. Advanced functions are all displayed whenever you press the on/off button, and they are selected in advance using the menu system. (More on those later.)

    The RX-800i/TBR features a built-in inclinometer, and a little angle icon in the lower right corner of the display will tell you the angle up or down to your target. RX-800i/TBR then does the math to calculate the true horizontal distance to uphill or downhill targets.

    Most shooters know that shooting downhill requires less hold-over than a flat shot at the same line-of-sight distance. It’s not quite as intuitive that uphill shots also require less hold-over. Bullet drop depends on the corrected horizontal distance to the target, instead of the line-of-sight distance. The RX-800i/TBR has you covered either way, because it displays either the ‘LOS’ (line-of-sight) range or the ‘TBR’ (True Ballistic Range - the corrected horizontal distance) to the target. When you know the ballistics for your specific rifle and load combination the TBR distance is the distance you want to use to calculate your holdover.
    If you don’t care to memorize your rifle’s holdover for known ranges, you can set the RX-800i/TBR to simply tell you what your approximate holdover is, measured in inches, centimeters, mils or minutes of angle. By working your way through the menu functions, you can select which rough class your cartridge is in based on the profile of its trajectory.

    The holdovers it provides are only approximations, because there are only nine ‘classes’ to choose from. For instance, the .308 150-grain and 168-grain loads are lumped in the same category and display the same holdover, but any .308 shooter knows that these two bullets do not have the same trajectory at 600+ yards. Personally I would never depend on it if I needed to put my first bullet into the vitals of a game animal beyond 300 yards, but if may come in handy for getting your rifle on paper at longer distances if you don’t already have a proper drop chart.

    In addition to the ‘RFL’ mode which calculates the corrected horizontal distance (and holdover, if desired) for rifle shooters, the RX-800i/TBR also has a ‘BOW’ setting which calculates the ballistics of arrows at ranges to 125 yards. Not being much of an archer these days I didn’t play with this function much.

    The RX-800i/TBR can also be used to accurately judge the width and/or height of a target using the Trohpy Scale. The Trophy Scale baseline can be set anywhere from 10”/25cm to 60”/150cm using the menu system. Once the baseline value has been set, the bracketing system will automatically adjust to changing distances to allow you to accurately gauge the width and height of antlers with ease.

    To test the RX-800i/TBR’s accuracy against real-world measurements I used some new-school technology: I employed Google Earth and it’s built in measuring tool to verify a large number of distances I had ranged and recorded in the field. I have no way of knowing just how accurate the measuring tool is in the Google Earth software, but considering all of my measurements were within 2 yards of those displayed by the RX-800i/TBR I would say it’s accurate enough.

    The aerial photo below shows the farm I referenced before, the various landmarks that were ranged, and the measured distances to said landmarks (RX800i/TBR in green, Google Earth in black).


    The RX-800i/TBR is a handy, palm-sized package that weighs next to nothing in your hand, and it’s got a rubberized texture on top for a better grip. It’s very comfortable to carry and hold, and the secondary ‘Mode’ button is located where it’s just about impossible to accidentally activate it while you’re ranging targets.

    The unit’s 6x magnification is fairly high for a monocular. It’s a little hard to hold steady at 6x magnification with one hand, and you’ll find yourself bracing your elbow on your chest or using two hands to steady it at small targets. It’s not a huge issue, but it is worth mentioning.

    As a result of the higher magnification, the RX-800i/TBR has a smallish exit pupil and it takes a steady hold to point it precisely at a small target. These are necessary tradeoffs however for a rangefinder that reaches out to nearly a half-mile. The extra magnification comes in very handy at those longer ranges, because it lets you aim precisely at a particular animal or tree instead of just pointing at an area and hoping you’re getting a good reading. Shorter-range laser rangefinders don’t need the extra magnification, but the RX-800i/TBR puts it to good use.

    In terms of target reflectivity, I was unable to find a single target that the RX-800i/TBR couldn’t range for me. Whether pointed at a tree trunk, a concrete slab, a brush pile, a vehicle of some sort or a fence post it always gave me a quick and consistent range to target. No problems there.