The dizzying plethora of gadgets and gizmos available to today’s shooter may make it difficult to select those that truly facilitate accurate and fast shooting, from among those that merely add aesthetic value. Few disciplines of shooting are more vulnerable to this dilemma than that of long-range precision marksmanship, or sniping. But even within this profusely merchandised specialty, the occasional new product comes along that is a definite keeper because of what it can do.
Pick up a book or read an article on sniping and one finds no shortage of well-meant advice, often complicated to the point of impossibility. To follow all of the proffered advice, one must not only have an impeccably documented and thoroughly researched data book, but also understand such heady topics as spin drift and atmospherics. While we can study at our leisure, when it comes time to shoot we are all victims of limited time and resources. There never seems to be enough range time to get our data books as accurate as we’d like even if there were enough ammunition to do so.
The Future of Sniping
Allow me to introduce the Horus Vision ballistic software chip known as the ATrag. No single contemporary instrument has had a more substantial impact on sniping than this chip. It fits into most standard PDAs (Personal Digital Assistants) and provides an advanced yet easy to use method of generating data or hold-off numbers required to accurately hit on the first shot. No more are we required to spend valuable days of range time in the endless pursuit of the perfect data book.
The ATrag accomplishes all of these feats by accounting for every constant that impacts the flight of the bullet. The constants found in rifles and ammunition are: muzzle velocity, ballistic coefficient, barrel twist rate, bore height and bullet weight. Most of these figures are easily acquired in knowing the manufacturer’s specifications of your rifle and looking at the published data on your ammo box or the ammo manufacturer’s website.
With this software chip, a sniper team doesn’t need a chronograph to get the muzzle velocity. All the shooter has to do is get a good 100-yard zero, move the target to 300 yards and annotate the correct data at that range in either MOA (minutes of angle) or MILs (millradians). Once the shooter has the correct come-ups for 300 yards, the muzzle velocity captured in the PDA is altered until the come-ups in the PDA match those generated at the same range. When done correctly, this process guarantees accurate data for any range. You read that correctly—at any range!
The other constants accounted for in the chip include: temperature, barometric pressure, humidity, latitude, direction of fire, wind speed, wind direction, inclination angle and range to target. I define all of these as constants because once they are accurately measured they cease to be variables. The only exceptions are wind speed and direction. While we can accurately measure these at the muzzle, no currently available device can accurately account for the effects of weather patterns and topography between the shooter and the target. Wind adds art to the science of sniping.
Latitude and direction of fire become important when the ranges reach out past 1,000 meters. When shooting past those distances, one must account for the coriolis effect. The coriolis effect is the influence the rotation of the earth has on the relationship between shooter and target as a function of projectile flight time. For example, if you zeroed your rifle due north at 1600m and then engaged a target due east at 1600m, the round would impact approximately 20 inches low. The reason for the point of impact shift is that the earth (and your target attached to it) rotates away from the fired projectile as it is in flight, lengthening the time of flight.
Once all the above constants are entered and stored into the PDA (a five-minute process) the software chip generates the exact hold within 1/100th of a MIL. For example, if you wanted to know the exact hold for 741 meters in 89 degrees with 42% humidity and 29.2 mrc of barometric pressure, you have it. Atmospheric changes entered into the PDA automatically update the shooting data, ensuring much more timely and accurate data than having to account for each change with a calculator—or just guessing.
Just about every rifle range in the military and civilian sector measures the distance from the firing line to the target in yards, yet on the battlefield we measure in meters. Not a problem for the ATrag. The chip can seamlessly transition back and forth between the two units of measure. No stubby pencils, no calculators, no complicated formulas laminated and stuck who knows where. The time investment required to generate all of the data made available by the ATrag would be enormous if not impossible. Now you can get your data for each meter or yard line, weather immaterial, in a process that requires you to fire six rounds (assuming no shooter error). It’s possible and it’s invaluable.
Other added benefits of the ATrag include the ability to store data on different loads and even different rifles; this is especially useful for military and police units. Should one sniper’s rifle break, he can quickly transition to either an unassigned weapon or borrow one from a fellow sniper. As long as the load’s muzzle velocity has been confirmed, all that’s required is a confirmation of zero in the new weapon and the ATrag will generate the data require to shoot any distance.
There is also a tremendous advantage if a sniper is required to shoot different loads in their rifle. For example, the BC (ballistic coefficient) of M118LR (Army issue .308 match ammo) is .496. Out of my once-issued M40XB it had a muzzle velocity of 2716 fps. In cases where M118LR wasn’t available, all that was required of me was to enter in the BC and muzzle velocity of what was available and I could continue to train. We de-linked the machine gun ammo and had accurate data to train and shoot it. This would be impossible without the ATrag.
The ATrag represents the future of sniping. Its value lies in the time it makes available for more relevant shooting and training (instead of data collection) and ammunition saved in the process. With the rising costs of ammunition and the ever-present competition for one’s time, the ATrag quickly pays for itself—but the accuracy and efficiency it fosters are the profit.
Visit www.horusvision.com for more.
The dizzying plethora of gadgets and gizmos available to today’s shooter may make it difficult…
by Stephen Hilliard / Sep 14, 2008