Sunday, May 17, 2015

Going the Distance

Going the distance

            Recently a debate has come to the surface regarding some new technologies that make extremely long shots, while hunting, possible. An argument has ensued regarding the distance some hunters are shooting, in that, they are pushing the boundaries of what is considered fair chase. Bullet design and construction have grown exponentially in recent years, along with technologies surrounding optics and rifle construction. It's reached a point where some are taking shots that a decade ago where unheard of.  In some corners, the sophistication has reached the point where some hunters are referring to their firearms as "delivery systems" while taking shots at animals at distances of over a half a mile away.
            The problem is some people are starting to question if this is really hunting or just killing. The notion of actually stalking an animal and getting in close to accurately judge the quality of the quarry, then taking an ethical heart/lung shot for a humane kill seems to have gone out the window for some. In its place, its become a contest, of sorts, as to just how far they can kill something. Pitting your woodsman (or woman) skills against a well tuned and weary critter is all but forgotten in some circles, as it’s become all about how far the shot was taken.
            My concern revolves around the skill needed to shoot great distances. Having studied ballistics for most of my life, I have an intimate understanding of what it takes to succeed with a long range shot. One thing that has fascinated me of late is the abilities of our modern snipers. Our military snipers, today, are taking shots that twenty years ago were unheard of. The question that is being asked by some is - "should those skills be applied to hunting?" I understand the physics and forces that go behind shooting a long distance, and my biggest concern is if the person pulling the trigger really understands the dynamic forces that come into play at some of the distances they are shooting. Will they end up with a clean kill, a clean miss, or a wounded animal, which at some great distance may be impossible to track.
            For example, I've often heard shooters speak of the bullets they use and how high the Ballistic Co-efficiency (BC) is, yet when they are pressed they have no clue as to what BC really means. Simply stated, the BC is a number that is reached mathematically and is a measurement of how well a bullet may be able to overcome air resistance and maintain its velocity while in flight. The higher the number, theoretically, the better the bullet will be able to keep its velocity. But, the BC is absolutely no indication of how a bullet will perform once it hits the intended target. The simple truth is that bullets are velocity driven; meaning the trajectory and energy are controlled by how fast they are going. Here's where things start to get complicated, as many match grade bullets currently produced are designed strictly for target shooting and are pretty much useless in a  hunting situation. Some of the manufacturers are even going so far as to label their match grade bullets for use in target shooting only and are not suitable for hunting applications. Going by the BC alone could lead to wounded, then lost animal, as the bullet may not be designed for hunting and on impact will not have the properties necessary to adequately penetrate the animal's hide and make a humane kill.
            Of greater importance to a hunter is the Sectional Density (SD) of a given bullet. Again the SD is a number reached through mathematical formula, which, in the case of the SD, also takes into account the bullet's relative mass. To avoid getting to complicated, the heavier a bullet is in a given caliber, the greater its SD, therefore, given the bullet's construction, the greater the penetration is, which equates to more knockdown power. For a hunting application, the bullet construction and SD are of paramount consideration. In some cases, as the SD rises the BC may actually begin to fall, yet the heavier bullets carry more kinetic energy and combined with proper construction for hunting equates greater stopping power.
            That is but one consideration when shooting long distances. As a bullet travels on other factors come into play. One is wind. Shooting 100 yards away as opposed to say 700 yards in a 10 mile-an-hour cross wind is completely different. At 100 yards the difference is measured in inches, whereas at 700 yards the "deflection" could be measured in feet. Wind Doping - estimating the wind speed and making the correct adjustments is something that does not come easily. To complicate matters, when shooting across great distances, the wind can and many times will shift and blow from different directions.
            Then there is the affect gravity can have on a bullet. Sir Isaac Newton, the infamous mathematician, physicist and astronomer, first laid down the fundamental rules regarding how gravity affects an object in the 17th Century, and those basic tenants still hold true today. Simply stated, gravity pulls at an object at a rate of around 32.17 feet per second. For a moment, let's consider a 150 grain 30-06 bullet that leaves the muzzle at 3000 feet per second, and whose intended target is 100 yards away. 100 yards is but 300 feet and with a bullet that is traveling 3000 feet per second, it will reach the target in 107 milliseconds or in .107 of a second. At that speed there is no way gravity can affect the trajectory of the bullet before it hits the target. But, now let’s say your range is 1200 yards or 3600 feet. The flight time is now 2.127 seconds. Can you calculate the affect gravity will now have on the bullet's trajectory? Remember, as you are calculating the affect, the pull of gravity is not the same everywhere.
            While you are at it, don't forget to calculate the gyroscopic drift when shooting across great distances, or the affect of the earth's rotation on the bullet. The point here is that when shooting really long distances there is much more to consider than just pointing the rifle at the target and pulling the trigger. There are a myriad of factors that can and will affect the trajectory of a bullet as the distance increases. At present I'm not taking a stand on one side or the other. My hope is those who attempt to shoot long distances have gone through some training to understand the factors that come into play as the distance increases, including whether or not the bullet will have enough energy to make a clean kill once it reaches the intended target. I understand under certain circumstances, to be successful, one may need to be ready to shoot up to 200 or a little further, but a half a mile away? I think this debate is just in its infancy as technology advances. It will be interesting to see how it goes....

Copyright 2015

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