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Long-Range-Finding And More

Long-Range-Finding And More
Gunwerks G7-BR2 Solves Many problems.

Apart from those issued to the military, most rangefinders are about the same. They give you the range, some better than others. Lately, they have shown the incline angle to the target. Then came the generation giving the come-ups in MOA or MILs or a BDC readout, along with the change needed at inclined angles. These were made possible by using pre-programed bullet-flight patterns that might fit yours or might not. All has changed with the introduction of the G7-BR2.

I have used many of the rangefinder models on the market since they were introduced. They were a boon to the hunter and to military users. Knowing the exact range to a target changed the game dramatically. Contrast the old method of trying to judge both the depth of the target and how much it covered between hashmarks. Still, you needed to know the come-ups or the holdover once the range was found. That meant referring to a table or a smart phone with a ballistics app. Lastly, you could just hold over some amount by feel, and let ’er rip!

Some riflescopes, such as some made by Zeiss, gave the range, and then supplied a red dot to indicate the holdover. Just put the red dot on the target and fire. You were still held to certain pre-programmed trajectory flights. Again, it might match yours or it might not.

What is needed is a rangefinder that allows you to program in the exact trajectory flight of your bullet—one in which you can program any bullet’s ballistic coefficient, muzzle velocity, sight height, etc. And one that will also monitor the environmental conditions as well as calculate the incline angle and change the come-ups accordingly. The folks from Gunwerks now provide one that does it all.

I have no idea how they packed so much in such a small unit, but they did. Some simple programing is required by the user accomplished using the four buttons on top of the unit. In use, however, just one push with the “fire” button gives all the information needed for the shot. It will also give you the hold off for wind as long as you know what the wind speed is. Wind hold off is accomplished by monitoring temperature, barometric pressure, angle, and then giving the shooter the wind hold in 5, 10 and 15 mph increments. It is the shooter’s job, however, to decide what the wind speed and vector are.

The owner’s manual states the ballistic calculations are good to 1,400 yards. The manual also states that the unit is good from 32 degrees F to 122 F. I contacted Aaron Davidson of Gunwerks about that. After all, the majority of hunting takes place in the fall and winter. The temperature is often much below 32 F. It seems the unit still works, but the display may respond more slowly.

In the range-only mode, the G7-BR2 gives the line-of-sight distance to the target, the approximate altitude, barometric pressure, temperature, and incline. They have coupled this with some innovative ballistic software for long-range shooting. The Gunwerks website is a wealth of information and long-range shooting videos.

The shooter wants to know not only the distance to the target, but the hold over. The G7 does this in a couple of modes: A ballistic turret (BDC) or MOA. The G7 will accept five different cartridge profiles. After choosing a profile, you enter the method to be used, the drag coefficient, ballistic coefficient, muzzle velocity, sight height, and zero range. If you’re using a ballistic turret, the current temperature and altitude are also entered. Thus, rather than trying to get close to some ballistic flight range, the G7 programs in the exact data of your round! The G7 then monitors the temperature, altitude, and incline and changes the holdover accordingly.

The G7 is a real breakthrough for the sportsman. Granted, you can use several means to gather the data to make shots at mid to long range, but it is time consuming. A first-rate range finder is needed along with a ballistic program residing on a handheld computer of some sort. An instrument such as a Kestrel is needed to monitor temperature and barometric pressure. Lastly, inclinometer giving the incline angle to the target is required. You read the distance to the target, note the angle, and then monitor the temperature and barometric pressure with the Kestrel. You then enter the distance, angle, temperature, and pressure into the handheld computer and ask for results.

The handheld computer gives you the MOA to dial, and the shot is taken. But the G7 monitors all that data once the button is pushed and gives the shooter the MOA to dial immediately. It knows the angle, the temperature, and the barometric pressure and calculates the MOA to dial according to those environmental conditions. No more need for a handheld computer, or a chart, or the Kestrel (except to estimate the wind).

Still, it is not quite that simple. The first problem is ranging. It takes some experience and a steady hold to get an exact range. And an exact range is necessary to place a productive shot on a target. Even the best rangefinders have a dispersion angle that often registers objects possibly in front of or behind the target. If the wrong distance is used to hit a target, even a small miscalculation will result in a miss or an unproductive shot. Shots at mid to long range take considerable practice and experience, and any significant wind, wind change at different ranges, or a switching wind will foil the entire enterprise. Ultra long-range is even more difficult. Know your limitations!

Mirage is extremely helpful in gauging wind near the target or between the target and the muzzle. But remember—mirage bends light. It may be the target you are aiming it is only a phantom, and the real target lies either to the right or the left of what you see by some small amount.

If the G7 calculates “lift,” “spin drift” and “coriolis force,” they are not mentioned in the manual. All of those forces must be reckoned with to hit ultra-long range shots. Briefly, wind moves the bullet in the direction of the wind, but lift will also move the bullet up some amount in a right-to-left wind and down some small amount in a left-to-right wind as well. Spindrift will move the bullet to the right some amount in a right-hand twist barrel. Coriolis force will move the bullet some amount as well depending on the direction of the shot and in which hemisphere it is taken. At mid-range (300 to 600 yards) and long range (600 to 1,000 yards), these affects are not large relative to targets about 20 inches square. But, along with wind, they become even more troublesome at ultra-long range.

The G7 is a 7X monocular. At the rear of the unit, just between the ocular lens and the body, there is a small, knurled ring. It is used to focus the optic. I found the glass to be very good. Resolution and contrast are good. It focuses well to the edges. I could detect no aberrations.

Among its other features, the display is bright enough to read on any background, an important requirement where many other rangefinders fail. But those who are colorblind might still have difficulty.

Bottom line: The G7-BR2 offers a tremendous advantage to the hunter who wants to extend the range beyond the traditional limits of 200 to 300 yards. It offers the entire data set required to make shots at mid to long range that, so far as I know, is not available elsewhere to the civilian shooter. It comes with battery, owner’s manual (both paper and CD), and all is included in a semi-hard case.
By Jacob Gottfredson

G7-BR2
Maker: Gunwerks
P.O. Box 22, Burlington, WY 82411
(307) 762-3240
www.gunsmagazine.com/gunwerks
Dimensions: 2.10″ x 4.45″ x 5.09″
Magnification: 7X
Weight: 14.3 ounces
Functional Range: 1,500 yards
Max Range: 2,000 yards
Max Ballistic Compensation: 1,400 yards
Min Temp for Ballistics: 32 F
Max Temp for Ballistics: 122 F
Beam Divergence: 2×4 Mrad
Target Modes: Near, far, continuous,
Display Backlight: LED
Battery: CR 123
Accessories: Case, neck strap
Price: $1,599

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