Environmental Hazards

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    Environmental Hazards

    By Darrell Holland

    Our high tech society has evolved in many ways, and hunters have had their share of advancements. High protein food plots for maximum horn production, sophisticated camouflage, alluring scent products, and last but not least, great leaps in rifles, cartridges and scopes for the long range hunter.

    Protein sources, scents and camouflage are no-brainers; they contain no ethical or responsibility clauses in their use. Rifles and the apparent license in their use should come with a disclaimer or better yet, a booklet on long range ballistics.

    As a custom gunsmith and long range shooting instructor I hear stories from scores of hunters shooting at big game animals at EXTREME ranges under horrific conditions and scoring one shot kills. There are numerous companies promoting extreme range hunting and intrepid hunters are eager to join the fraternity and receive their merit badge. While there are a few extremely capable individuals promoting such shooting/hunting ethics, we must keep in mind the ability and knowledge of the hunters we are enticing.

    Having run a long range shooting school for a number of years, we see a pretty good cross section of hunters come and go, many with years of shooting and hunting experience but lacking in the understanding of applied ballistics and hazardous environmental conditions that they face when going afield. It’s a fun and exciting thing to “ring steel” at 600-1000 on a windless day at 70 degrees from prone or bench rest conditions and another thing to do so at 20 degrees in 12 inches of snow with a 3-5 mph breeze blowing left to right and shooting over your pack.

    Over the years we’ve had some great shots attend our schools: military snipers, police marksmen, competitive shooters and some damn good country boys who grew up with a rifle in their hands. Our range facilities allow us to shoot under real world conditions. Shooters tackle switching winds as well as angular conditions complimented by irregular and broken ground. These are tough conditions to shoot in and make consistent hits at 500-600-700 yards, not to mention doing so at 875-900 and 1000 yards.

    Many folks have not a clue as to what the bullet is doing at 875 yards v/s 900 yards. At 900 yards a mere 2 mph change in the wind between you and the target can change bullet impact 10 inches. How many of these genetic links to Carlos Hathcock understand the effects of barometric pressure, temperature, elevation and humidity on their bullet’s flight? I can assure you not many! Is it ethical then to be shooting beyond our knowledge base? Does the cost of the hunt, or the last day of the hunt give you license to shoot beyond your capabilities? If you muttered a feeble “yes” to the above questions, you’d better sharpen your pencil and take good notes.

    In an attempt to educate those hunters who walk the razors edge, let’s go hunting and explore the pitfalls in an average mule deer hunt at long range.

    Our test hunter is shooting a 300 Winchester Magnum with a 180 grain Nosler Accu-bond at 3000 fps. chronographed at 70 degrees. He is using 72.5 grains of R/L #22 with a Remington 9 1/2M primer. He zeros the rifle at 200 yards and using Sierra’s Infinity 5.1 ballistics program plots the trajectory of his rifle to 1000 yards for his Colorado hunt. Confident that he has done everything right, he double checks the numbers: B/P 29.0, altitude 4500', temperature 20 degrees, humidity 20%. Yep, she looks good as he tapes the data sheet to the rifle’s stock. He’ll be hunting the wind swept prairies of eastern Colorado.

    It snowed 12 inches the week before and a warming spell created a crust on the snow, making walking difficult and noisy. An hour from camp our hunter spies a great buck in the distance. Our hunter crouches low in the sage and walks to the side of a small hill, gaining a slight elevation advantage and better shooting position for the shot. It’s 17 degrees outside as he struggles with numb hands to free his range finder from his coat pocket. Shivering from the cold and the excitement of seeing a world class buck, he zaps the laser rangefinder and it fails.

    His warm breath condenses on the eye piece and freezes. Twice more it flatlines, and finally on the fourth attempt he gets a reading. The bold red numbers read 775 YARDS. He’s confident he can make the shot. He’s seen it done on TV many times. He recalls the success stories of fellow hunters at the gun club who have taken game at greater distances. He checks his data chart and dials the correction. At 775 yards the bullet will drop 123 inches, the hill is protecting the hunter from the 3-5 mph breeze that is blowing, the 12 inches of snow has covered the bunch grass and the stiff sage brush offers no indication as to wind velocity or direction. Focusing on the deer, our hunter does his best to provide the perfect trigger squeeze under the frigid temperatures.

    Let’s examine a few of the environmental hazards involved in the above shot.

    1) Never rely on a single reading from the laser rangefinder when it has flatlined several times before. We MUST get consistent readings to confirm an accurate range to the target. The error factor is too great to risk the shot of a lifetime. A mere 25 yard change in the distance to the deer can result in an 11 inch point of impact change.

    2) Our shooter has loaded his ammunition with R/L #22, not the best powder choice when it comes to temperature sensitivity. With a 53 degree change in temperature from his chronograph testing at 70 degrees he may well experience a 100 fps loss in velocity or MORE. With a 100 fps loss in velocity the bullet will drop an additional 9.75 inches.

    3) The unnoticed left to right breeze of just 3-5 mph will cause a 14-15 inch deflection in our bullet’s flight. Keep in mind that it is very difficult to accurately gauge the wind beyond the shooter especially over broken/irregular ground with hills and timber. A full value 10 mph wind will deflect the bullet 38.44 inches under the above conditions.

    4) Add in a little flinch, imperfect trigger squeeze, or the rifle shifting under recoil from the less than perfect shooting position over the pack, and who knows where the bullet may strike?

    The chances of our hunter connecting with the buck are pretty slim in my opinion. Wouldn’t you agree?

    Let’s stretch the barrel a bit more and make the mythical 1000 yard shot under the same conditions.

    At 3000 fps bullet drop is 249.84 inches, at 2900 fps (remember the 100 fps loss from our temperature change) drop is 269.87 inches--a 20 inch difference! Wind drift in a full value 3-5 mph wind is 26-27 inches, provided we have a consistent wind ALL THE WAY TO THE TARGET. Miss the target distance by 25 yards, add 18 plus inches to the drop.

    These are point of impact changes with just a 100 fps change in velocity and a 3-5 mph breeze. Experience a 1.5 point change in barometric pressure and drop at a 1000 yds. increases to 279 inches. Hmm, are we starting to see the severity of changing and unpredictable conditions at long range? Cogitate on a 600 yd. uphill 20 degree shot, with a 7:30-1:30 quartering wind at 10 mph. Does bullet lift come to mind? If so, how much?

    Ask competitive long range shooters how often they hit the X-ring with the first shot in competition? “Not very often,” should be the reply! Keep in mind they are shooting at an EXACT 600-800 and 1000 yds. with wind flags from a very stable position with very little adrenaline/excitement flowing in their veins.


    To reasonable shooting distances, at ranges up to 600 yards, a temperature/muzzle velocity change is the most important factor to be considered. Slight changes in elevation, humidity, and barometric pressure have very little effect on the bullets flight to 600 yds. with magnum velocities. With consistent and determined practice one can become quite proficient on game animals to 600 yds. Beyond that, it takes tremendous skill and experience combined with a little luck to make consistent hits at 800-900 and 1000 yds.

    If you doubt this, take 12 inch squares of cardboard and attach them to a wooden stake. Have your hunting partner place them at different yardages (600-1000 yds.) and different angles to the shooter. Range and calculate the MOA correction for drop and drift and fire away. It should be a humbling experience. This 12x12 inch square represents the kill zone of a deer or antelope.

    This simple test will allow you to assess your proficiency and determine your range limitation. Set aside your ego and be honest with your capabilities. If you can consistently keep ALL of your shots in the 12x12 inch square at 600 yards, but hit 2 out of 5 at 700 yards, your range limitation under ideal conditions should be 600 yards. On the other hand, if 450 yards is the extreme range at which you can keep all your shots on the target, stand tall. You are ahead of 95 percent of the shooters out there given the same test. As true sportsmen we need a moral compass to guide us in our long range shooting pursuits; this test can help us obtain that virtue.

    Chronograph your ammunition at different temperatures. 100 degrees for summer antelope, 70 degrees for normal conditions and put several cartridges in the freezer overnight and keep them on ice with a thermometer at 20-30 degrees. Note and record the muzzle velocities with these temperature changes. Create data cards for each muzzle velocity.

    The best powders for extreme temperature changes are the Hogdon series of EXTREME powders. They include the following: H-4895, Varget H-4350, H-4831, H-1000, Retumbo- Benchmark and H50BMG. These powders will provide the most consistent velocities in a wide range of temperatures. It is the responsibility of the serious hunter/shooter to check his or her ammunition for velocity changes when gunning at long range.

    Above all, practice!!! One can never get enough practice. Do so under realistic outdoor conditions and be honest with your evaluation. Competence comes with perfect practice. No one packages or bottles it! Keep good records of your shooting, note temperature, wind, barometric pressure, humidity and the MOA correction needed to make a center hit under the above conditions. You will see some interesting comparisons when reviewing these notes.

    Don’t be a fair weather shooter! We see a majority of shooters who, when the wind is up, or it is raining, simply punch the alarm, roll over and catch a few more ZZZ’s. Hmmm, they are missing a golden opportunity to see the effects of rain, temperature, humidity and B/P on their shot. Do we stay in the tent when it is raining or snowing? When the weather conspires against you, don your foul weather gear and get some experience. It can make the difference between success and failure in the future.

    Wounding an animal is a heavy burden to carry and rightfully so. Know your limitations and never allow someone to push you beyond your comfort zone. Surgical one shot kills are what we are after. “Just get a bullet in ‘em” should be removed from our vocabulary! If in doubt, stalk and get closer, there is no shame in a 450 yard shot.

    Until next time, shoot straight and be safe in the great outdoors.

    Darrell Holland is a Custom Riflesmith and designer of Advanced Reticle Technology in Leupold, Schmidt & Bender and NIGHTFORCE rifle scopes. Darrell offers an intense 4 day shooting school that is ideal for long range hunters and tactical enthusiasts.

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