The One Mile Prairie Dog
By Mike Brust
©Copyright 2011, The Varmint Hunters Association, Inc.
A few years ago I qualified for the V.H.A. 1000 Yard Club. It marked the successful conclusion of almost three years of effort that taught me how different ultra-long range shooting is from what we normally would consider as simply long shots.
The canted base and generous range of precise scope adjustments allowed the author to “dial in” on targets to beyond 1,800 yards.
In the process I learned a lot about the equipment that makes this type of shooting not only possible, but amazingly predictable. While there still is a considerable amount of preparation and shooting skill required, connecting on a tiny target in the next ZIP code would be very difficult without the help of some of the latest technology in rifles, scopes, and accessories. Frankly, a lot of it has been developed in recent years in order to satisfy the need for top-quality military sniper equipment.
I also have learned that many people have absolutely no concept of how far 1,000 yards actually is. A friend, after seeing my prominently displayed V.H.A. 1000 Yard Club certificate, said he was just amazed that I could hit such a small target at “farther than the length of a football field.” At that point I realized I needed to make another shot, and in a scale that everyone understands: miles. Actually, it probably just provided a good excuse to take the next step. So my quest for the “one-mile prairie dog” began.
One mile is exactly 1,760 yards. Much of what I learned from shooting at 1,000 yards could be applied to this distance, but there also were new challenges. First, my 1,000-yard cartridge, a .220 Swift, wouldn’t cut it. It basically was out of gas after 1,000 yards, so I clearly needed a bigger bullet/cartridge to carry the necessary velocity, accuracy, and energy out to almost twice that distance. After considerable research, I decided that the 6.5-284 Norma (or Winchester) would be the ideal round for the job. It is a favorite for 1,000-yard target shooting, with a reputation for accuracy, moderate recoil, and superb downrange ballistics, especially when pushed out of a long target barrel. Unfortunately, not being independently wealthy meant that having that type of rifle built was beyond my means. However, within weeks of coming to this realization, my next issue of The Varmint Hunter Magazine™ announced a new rifle from Savage called the Precision Target Rifle. Besides being reasonably priced, it had everything: a stiff single-shot short action, a massive 30-inch target barrel, a special AccuTrigger that could be adjusted down to ounces, a flat-bottomed laminated stock designed to ride well on bags, and unbelievably, in the F-Class version it was chambered in none other than the 6.5-284! Subsequent reviews confirmed its long range potential, with 500-yard groups that rivaled what some rifles shoot at 100 yards. My one-mile quest was back on track.
Black Hills 6.5-284 Norma ammo proved to be superior to the author’s handloads..
After acquiring a new F-Class Savage Precision Target Rifle, the next most important component certainly would be the scope. Besides the need to be optically exquisite in order to see and hold on small rodents a mile away, several other critical elements would be necessary. A 142-grain Super MatchKing 6.5mm bullet, pushed out at 2,975 fps, drops 122 feet at 1,800 yards. That’s equivalent to 75 minutes of angle. If I planned to use a scope that I could sight in at 200 yards and then “dial out” to 1,800 yards, it would need a minimum of about 73 minutes of angle of internal elevation adjustment, and that’s assuming I could externally adjust it to be at the very other end of its adjustment range for close shooting. There are very few scopes available that have that capability combined with quality optics, adequate magnification, fine crosshairs, precision adjustment, and absolute repeatability. While some of the premium scope lines have tactical and/or long range scopes that met most of these requirements, one brand exceeded everyone else’s specifications in virtually every category. Nightforce scopes, particularly the NXS 5.5-22x56, appear to be designed just for this type of ultra-long range shooting. It has 100 MOA of internal elevation adjustment, crystal clear optics, a calibrated NP-R1 reticle (that proved invaluable during the actual shooting), and precise adjustments in exact MOA graduations.
Although expensive, I knew I had the right scope when I was setting it up. I was using one of Ken Farrell’s excellent canted solid steel bases to externally adjust the scope to be at the “bottom end” of its elevation adjustment when sighted in at 200 yards. I noted the setting, and then dialed the scope until it stopped at the other end of the internal adjustment to determine how much travel I had available. I made several adjustments in both directions and also did the same with the windage adjustment before returning it to the original setting. After all those adjustments, including several against the stops, I shot again at 200 yards to see how much the group moved. It didn’t. The rifle printed a tight three-shot cluster right on top of the group I shot when I began.
I had the rifle, I had the scope, and the project was coming together. Because I reload, I had hoped to start building loads with US-made Hornady components. They had just come out with their own 6.5-284 brass, and their 140-grain A-Max bullets would be an excellent choice for this application. Unfortunately, because of military demand I believe, some of those components remained on backorder as everything else fell into place. Although the project had been delayed a year because of some technical problems and weather issues on our first trip, by the next spring the ammunition situation was the only major issue that was still unresolved. But then The Varmint Hunter Magazine™ came to the rescue — again. The Press Releases section of the latest issue announced that Black Hills Ammunition Company had just come out with loaded 6.5-284 Norma ammunition using the legendary Sierra 142-grain Super MatchKing bullets. Although I have always believed I could build better cartridges through precise reloading practices and a carefully selected combination of components, I was running out of time, and Black Hills Ammunition has an excellent reputation, so I ordered some of their Black Hills Gold loaded ammunition. It was delivered quickly, and I was delighted to find that it equaled or even surpassed the quality of my meticulously constructed handloads. I had been concerned that performance would suffer because the bullets were seated well short of the lands. I also was concerned about achieving enough velocity because the recommended powders I had tried had fallen just short of the optimum 2,950 to 3,000 fps I was looking for. However, the first five shots of the Black Hills ammo chronographed from 2,961 to 2,976 fps. Accuracy was as good as my handloads, and the velocity standard deviation was actually smaller!
Setup for one-mile shooting. Range determination to distant prairie dog towns was accomplished with the help of a computer and GPS unit.
Although I had the rifle, scope, and ammunition ready to go, there still were a lot of little details that had to be tied up if the project was to be successful. A quality spotting scope for my spotter and a rock-solid bench and rest would be essential. And, as I had learned when shooting at 1,000 yards, range markers also would be necessary equipment.
Another thing I discovered when I was trying to accomplish the 1,000-yard shot was that even in open prairie and pasture land, there are very few places where a safe 1,000-yard shot could be taken, and then it always seemed to be perpendicular to the wind. Setting up a mile shot would be that much more difficult. Added to that was the concern that pacing off 1,760 yards just wasn’t practical. With valleys, fence lines, rivers, washes, and a myriad of other obstructions, it would be very difficult and time consuming to confirm the exact distance prior to a shot, even with a laser rangefinder. Those challenges led to an unexpected new piece of equipment for this project: my computer and an Internet map service.
The “Taj Mahal.”
I used mapcard.com (also known as mytopo.com) but there are several topographic map services on the Internet. Because I knew from previous South Dakota visits approximately where the dog towns were, I was able to bring up topographic maps of each area, which showed all of the high ground (potential shooting sites) around each town. From that I could determine roughly how far away I could get and still see and safely shoot into the dog town. And with satellite photo overlays, “map tools” and GPS coordinates, I could do much more. First, with satellite photos so detailed that I could actually see individual prairie dog mounds, I could confirm the exact boundaries of each dog town. Then, by choosing a spot either in the dog town or on a nearby bluff, and then selecting a computer tool, I could measure the straight-line distance between a shooting and target point, right down to the foot. This allowed me to select different spots in each dog town and then measure out exactly one mile to locations that provided an unobstructed shot — before I even left home! In some towns I could also select different angles that might be more favorable to the wind direction while I was there. Finally, I could identify the exact GPS coordinates for each location, punch them into my GPS, and then drive or walk right to them once I got there. No pacing or measuring should be necessary. Before I left for South Dakota I printed topo maps and satellite photos of each area with the GPS waypoints noted.
After two years of preparation, with the truck packed with rifles, ammo, and a lot of high-tech equipment, we finally left Wisconsin for the wide-open spaces of western South Dakota. Fortunately, we didn’t need to also haul a lot of camping gear because the rancher and good friend whose ranch is host to some of the dog towns allowed us to stay at his bunkhouse right on the ranch (affectionately known as the Taj Mahal). And with gas at close to $4.00 per gallon, any weight/mileage savings were more than welcome. My nephew and regular hunting partner Nick was along to help with spotting on the long shots, and our sons Peter and Adam came along to accomplish some real rodent control with higher percentage “close” shots. Nick’s son, Adam, age 12, joined the 500 Yard Club on this trip with a 608-yard shot on a jackrabbit.
Because our previous trip to the area had us shooting in record 118 degree temperatures, we were actually happy with the 95 to 100 degree temperatures forecast for this trip. However, we were rather concerned with the forecast of high winds that promised to make long-range shooting challenging … at best.
For several years western South Dakota had suffered from a severe drought. However, this spring brought record rains and high water. We arrived to find tall grass, green pastures, and bridges out. Navigation was an issue and the grass didn’t help with spotting dogs or bullet impacts, but it was sure nice to see healthy livestock, stockpiles of new hay bales, and abundant wildlife.
Adam joins the 500 Yard Club.
We immediately set up four-foot tall high-visibility markers at the GPS waypoint locations in the dog towns and then drove to the one-mile-distant waypoints to mark the shooting locations. It worked perfectly and we had exact 1-mile distances confirmed and marked in less than an hour! The only problem occurred in one case where river-bottom trees were high enough to obstruct the view of a target area. Unfortunately, the one-mile shooting locations were so far from the dog towns that they didn’t present the opportunity for the kids to take shorter shots from the same areas.
The other problem was the wind. At its lightest it was 15 mph throughout the whole time we were there. Based on my previous experience with .223 caliber bullets, I had little hope of any consistent accuracy at ultra-long ranges. For shorter shots we were able to work around a dog town to minimize the wind vector, but the 1-mile shots offered few options, and none were good. However, given that we had already spent a small fortune for the gas to get there, we decided to give it a try. One plus was that any potential mirage problems were effectively “washed away” by the wind.
The first shot at one mile struck about “hole high” and about 30 feet to the left because of the wind. The fact that the elevation was right on confirmed that both the calculations from my Sierra Infinity ballistic software and the MOA adjustments of the Nightforce scope were accurate. Had I calculated and then adjusted for the wind speed and angle, I suspect the impact would have been pretty close to the unsuspecting varmint. However, it was easier to confirm the first strike and then adjust zero accordingly, which was done on subsequent shots.
As expected, the wind played havoc, but not nearly to the extent that I thought it would. Although the wind was stiff, and varied in both velocity and direction over the course of a mile, once the crosswind was adjusted for, windage variations were usually less than 2 feet from shot to shot at the same distance and angle. Amazing! From a mile away in a brisk crosswind, most bullet strikes were right on or around the prairie dog mound.
Over the course of two days, a couple of hundred shots were attempted at one mile or longer, and although we did not confirm a kill, probably 70 percent of the shots would have gone into a 3-foot circle. There were a couple of instances of observed hits and even “flipage,” but no carcasses were recovered. Because the 142-grain bullets lose about two-thirds of their velocity at that range, a direct hit, preferably to the cranium, probably would be necessary to anchor a prairie dog enough to keep him from getting down his hole. Under better wind conditions, however, I have no doubt that a confirmed one-mile prairie dog is not only possible, but very likely.
There were a few things that differed from shooting .223 bullets at 1,000 yards. First, a 142-grain Super Match-King bullet provides a much more visible impact signature than a 55-grain Ballistic Tip. Unfortunately, it also must have been much more disturbing to the targeted prairie dogs. They didn’t seem to mind the smaller impacts at 1,000 yards, but disruption of a much larger bullet landing right next to them usually sent them down their holes for extended periods of time. The fact that we were there late in the season after they had already endured other shooters probably didn’t help either. This, however, did present a new problem. To switch to a new target location, even 20 or 30 yards away, required a whole new set of windage and elevation adjustments because of the acute trajectory and the wind vectors.
Another difference is the additional time it takes the bullet to get there. It takes 3.4 seconds for a 142-grain SMK to travel one mile when started at 2,965 fps. That allows plenty of time to recover from the recoil, reacquire the target in the scope, and wait for the bullet impact. In most cases, having a spotter was really unnecessary. In fact, because the Nightforce scope was so clear and the NP-R1 reticle provides MOA hash marks both vertically and horizontally that correspond exactly to the graduated adjustment knobs, adjusting for subsequent shots was amazingly simple. All I had to do was level the crosshairs back on the prairie dog and watch the impact. If the bullet struck five marks (MOA) low and two marks left (two MOA each), it was a very simple matter to dial up 20 clicks and right 16 clicks. Because the adjustments were so precise, with no lag or overtravel, the next shot usually was within inches of the target. Again, without the wind variations and nervous prairie dogs, scoring quickly should not have been a problem, although the inherent accuracy of any rifle will always be a factor. All else being equal, a half-inch rifle becomes a nine-inch rifle at 1,800 yards.
So I returned to Wisconsin without posing for a picture kneeling next to a downed critter while holding a hastily hand-drawn sign with a number in excess of 1,760 yards. However, other than that detail, the project exceeded all my expectations. I never would have believed, especially in a stiff breeze, that I would consistently drop shot after shot into the area the size of a washtub — from a mile away — with an over-the-counter rifle and “factory” ammunition. Varmints beware!