WHILE SHOOTING prairie dogs with a wide variety of very fine marksmen over the years, I’ve yet to see any shooters able to hit more prairie dogs than they miss beyond about 350 yards in typical conditions.  Somebody recently asked for an explanation, because they’d seen the same thing themselves.  This seemed a good opportunity to discuss centerfire rifle accuracy.

Those prairie dog shooters have included top military snipers, long-range target competitors who’ve won their share of medals and trophies, and a Hall of Fame benchrester who recently set a world record.  Their rifles have often (though not always) been custom-made, sometimes by Famous Gunsmiths, so have been very accurate.  What’s the problem?

Actually, there are two problems, the limits of accuracy and wind.  Let’s look at accuracy first.  These days shooters normally define centerfire rifle accuracy by the width of 100-yard groups, measured center-to-center of the widest shots.  This may not be the best way to measure accuracy, but most of us understand the concept, so it will do here.  These days probably 90% of hunters shoot 3-shot groups, and most prairie dog hunters are satisfied if their rifle averages ½” or less, but that really isn’t all that accurate, for several reasons.

First, 3-shot groups don’t truly determine how far the widest shots will spread.  Yeah, we’ve all heard the reason to shoot only three shots is because barrels “walk” as they heat up, especially sporter-weight barrels, so three rounds reveal a rifle’s “true” or “practical” accuracy.  This is why so many shooters allow time for their rifle’s barrel to cool down between shots or groups.

While some barrels do warp as they heat up, good barrels don’t, whether factory or custom.  Instead, firing more than three shots results in larger groups because the more shots fired, the more likely some will actually land near the rifle’s outer limits of accuracy.

This can be proven in several ways, but the easiest is to put up a target at 100 yards, then tape another identical target over the first.  Fire a 3-shot group, then remove the outer target and put up a new one.  Do that three more times, and you’ll have five targets with 3-shot groups, and one with a 15-shot group.  I guarantee the average diameter of the 3-shot groups will be smaller than the 15-shot group, no matter how long the barrel cools between shots.

Short-range benchrest matches require an average of 5-shot groups, and to be competitive even in local benchrest matches, a bench rifle has to average less than .2” for 5-shot groups at 100 yards.  Bench rifles have heavy, stress-relieved custom barrels immune to heat-warping, and fire bullets far more uniform than any hunting or even mass-manufactured “match” bullets, yet their 5-shot groups will also average larger than 3-shot groups.

Over the years I’ve discussed how many shots must be fired to establish a rifle’s basic accuracy with several statisticians, all shooters, and the answers have differed.  None, however, had the slightest confidence in 3-shot groups.  Instead an average of several 5-shot groups was the minimum suggested, but one guy said a single 7-shot group would be an excellent start, and another thought a 9-shot group revealed sufficient data.

My own shooting with various factory and custom rifles, including my own benchrest rifle, forced me into similar conclusions several years ago.  Anymore, when starting to work up loads for hunting rifles, I start with 4-shot groups, because three shots too often result in one of those “one-holers” hunters carry in their wallet.

I’ve shot too many 3-shot one-holers that, with further experimentation, proved to be products of pure chance.  Oh, once in a while some rifle would do the same thing over and over again — a light-barreled Ruger No. 1 .25-06 would repeatedly put three 75-grain Hornady V-Maxes into the magic ½” or so — but most of the time subsequent groups average larger, often much larger.

Once a couple 4-shot groups indicate a prairie load might work OK I shoot a 10-shot group.  Seven or nine shots might work as well, but humans have relied on base-10 numbering for a long time, partly due to (usually) having 10 fingers.  Ten-shot groups reveal far more about a load’s actual spread potential than any number of 3-shot groups.

Plus, 10 rounds will heat heavy barrels enough to indicate whether they’ll change point-of-impact when shot hot on a prairie dog town.  And yes, even some heavy barrels will warp when hot.  I once owned a factory .22-250, made by a company with an excellent reputation for accuracy, that shifted POI enough to miss dogs at 150-200 yards after a few shots, even on cool spring days.  A factory varmint rifle capable of 10-shot groups under an inch is pretty darn accurate, and under ¾” is very accurate.

The other factor is ammunition.  Benchrest rifles capable of averaging five shots in .15” at 100 yards don’t shoot the same kind of ammunition most of us use on prairie dogs.  The cases begin life far more uniform than the cases most varmint shooters use, then are “uniformed” even more until essentially identical.  After their first firing, they’re necked-sized in special dies, and the primers often seated with a gauge indicating the amount of leverage.  And they’re definitely not loaded with the cheap bulk-pack bullets many prairie dog shooters buy.

They’re also not cranked out on a progressive press, but accurate ammo can be produced pretty rapidly in volume.  I mostly use Redding “S” bushing dies, paired with seating dies that hold the bullet in alignment instead of just pushing it into the neck.  As a result, a lot of my PD ammo comes out with .003” or less of bullet runout, but that isn’t benchrest-grade alignment.

The bullets aren’t benchrest-grade either, and neither is the brass.  I may sort it for fairly even neck thickness, but I ain’t buying 1000 Lapua cases for shooting rodents.  And I’m also not going to check 1000 rounds with a run-out gauge, straightening any outliers in my TruAngle tool.  Like most of us, I’m just going to load ‘em and shoot ‘em.

As a result of all this, 10 shots in ¾” at 100 yards is about all most prairie dog rifles will do.  I’d bet that’s better than most rodent rifles, but let’s assume it’s average.  That means the rifle is capable of keeping all its shots in a little over 2” at 300 yards, and while some prairie dogs are more than 2” wide, most aren’t.  Now, PD’s are longer than they are wide, which ups the odds somewhat, but rifle accuracy limits essentially mean our aim and trigger control has to be perfect to hit every prairie dog at 300 yards.

Now, let’s throw in the wind.  If we get out there early enough, the air may be totally still, or close to it, but by mid-morning a “calm” day on the high plains normally means a breeze of 3-5 mph.  Let’s assume we’re shooting a typical .223 Remington load with a 50-grain plastic-tipped bullet at 3400 fps, on a town 3000 feet above sea level and a temperature of 70 degrees Fahrenheit.  A 3-mph breeze at 90 degrees to our shooting will push the bullet about 2-1/2” off-course at 300 yards.  This can be compensated for by holding the edge of the vertical crosshair just off one side of the dog, with a little space between reticle and dog.  Increase the breeze to 5-mph and the same bullet drifts around four inches.  Now a “one dog” hold is necessary, with the width of a dog between the center of the crosshairs and the target dog.

However, mild plains breezes usually aren’t steady.  Instead they often vary 3-5 mph, or even more, and can change while the bullet’s in the air.  The time-of-flight of our 50-grain plastic-tip is around 1/3 of a second, and adding trigger-reaction and lock-time probably result in a total of a half-second.

Either a side-of-dog hold or a one-dog hold will hit some dogs, but also miss some.  If we’re patient enough to wait until we’re sure the wind’s the correct speed for one hold or the other, then squeeze trigger without pulling the shot during that instant, and the wind holds throughout the half- second between the time our mind says “go” and the bullet travels 900 feet, then the bullet will probably hit the dog.

Still, a good shot with a rifle capable of keeping all its shots in 2” at 300 yards will hit more dogs than he misses.  (Or she misses.  I’ve known some very good female prairie dog shooters, including my wife Eileen, who was once awarded the nickname “Badass” by famous benchrest gunsmith Allan Hall after she popped a bunch of PD’s one afternoon at ranges from 300-350 yards.  That’s pretty strong language for Mr.  Hall.)

Things become even more complicated in the afternoon, when the wind velocity normally picks to around 6-10 mph, and sometimes even more.  If the wind’s varying (and it usually is) the percentage of hits drops considerably.

Now, higher muzzle velocities and ballistic coefficients reduce wind-drift, the reason I prefer the .204 Ruger to the .223 Remington for general prairie dog shooting.  A 40-grain .20-caliber plastic-tip at 3800 fps reduces drift from a 5-mph wind by about an inch at 300 yards, and a side-of-dog hold will work more of the time, even if the breeze varies 3-5 mph.  Time of flight is also reduced slightly, giving wind-switches less time to do their dirty work.

Of course, we can also use a really high-BC bullet, and “Ackley Improve” the .223 for a little more zip.  A 75-grain Hornady A-Max at 3000 fps will drift about ½” less at 300 yards than the 40-grain plastic tip from a .204, but I still prefer the .204, because its flatter trajectory makes knowing the exact range less critical, and time-of-flight is slightly shorter, so shifting winds can plays as many tricks.

An even trickier wind problem is a “vertical component,” caused by uneven terrain like cutbanks and valleys.  I’ve even seen the air start to “boil” on warm afternoons above relatively gentle hillsides, sending air currents in several directions, making hits almost impossible at 300 yards.

Once in a great while the wind remains calm all day.  I can remember two occasions like that over 40 years of prairie dog shooting, though there were undoubtedly more.  On one of those days Eileen and I were shooting with the late Ian McMurchy, a writer, photographer and long-range shooter from Saskatchewan, and we all hit a high percentage of dogs beyond 400 yards.  I was shooting a very accurate .223 Remington with a Ramshot scope that had a grid-type reticle, and during one stretch hit over half the dogs on a small hill between 550 and 600 yards away.

In another year in the same country, one of my rifles was a heavy-barreled .22-250 with a 6-24x Zeiss scope with “turrets.”  I’d really been able to wring out the scope’s clicks, and on that calm afternoon the odds were against dogs at 500.  This was on an industry shoot where a Cooper .22-250 would be given to whoever made the longest shot with any .22-250, so I started stretching the range.

Eventually a big dog stood up at 820 yards, and after twirling the elevation turret the first bullet landed right at its feet, but about 2” to the right.  I quickly shot again without adjusting the scope, before the very slight breeze could change, holding a little higher and 2” further left, and the dog flopped over.  Unfortunately, my friend John Haviland was in the next valley, shooting with another .22-250, and after about 50 rounds managed to kill one at a little over 1300 yards, and he got the Cooper.  But such near-calm conditions are really rare.

All of this is why I don’t shoot very often at prairie dogs beyond 400 yards anymore.  The occasional hits aren’t worth the extra ammo, and besides, most of the places I shoot prairie dogs these days are private ranches.  The ranchers allow prairie dog shooting because they want us to reduce the number of dogs, and under normal conditions really long shots don’t hit many dogs.  Which is why my prairie dog cartridges have shrunk considerably over the years.  I rarely use the .223 anymore, spending probably 80% of my time with the .17 Fireball and .204 Ruger, while the .17 HMR and Hornady Hornet used some on towns that haven’t been shot much.

All of these basic principles also apply to long-range hunting of any sort.  We’ve got to consider a rifle’s real potential for accuracy, along with wind-drift and time-of-flight.  While heavier, longer bullets drift in the wind far less than typical prairie dog bullets, wind-drift still increases rapidly at ranges beyond 400 yards, almost doubling between 600 and 800 yards with a 6.5 Creedmoor shooting a typical super-sleek 140-grain bullet.  With big game rifles, absolute accuracy at 100 yards a smaller factor than with varmint rifles, but wind is always the big problem.