N YEARS of using various rifle ranges, only a handful of other people have put out wind flags when bench-testing a rifle, even when the breeze was turning round and
round. This includes many serious guys that use anal-retentive handloading tools such as micrometer seating dies, bullet-alignment gauges, and a computerized electronic
Here's a clue: The wind makes more difference than any of that stuff.
Don't believe me? A mild, erratic breeze of 5 miles per hour can open up 100-yard groups over half an inch — in addition to whatever accuracy your rifle, handload, scope
and shaky self are capable of producing. And that's when shooting a high-velocity rifle with a relatively heavy bullet with a high ballistic
coefficient. A .223 Remington with a relatively low-BC varmint bullet, or any rimfire cartridge, is much more susceptible to the vagaries of the wind.
Wind deflection can be precisely calculated, given all the particulars. I used the Sierra Infinity ballistic program on my computer to calculate the wind-drift of
a .270 Winchester shooting a 140-grain Nosler Ballistic Tip at 3000 fps. The "environmental conditions" punched in were 29.95 inches of barometric pressure, 70 degrees
F., an elevation of 1000 feet above sea level, and a wind velocity of 7 mph. That probably comes close to the average range conditions on a sunny summer morning across the
USA. The program said that a 5 mph breeze blowing at 90 degrees to the range blows the bullet off-course 3/10ths of an inch.
Now, 5-mph is barely enough to stir the smaller twigs on a tree branch — if the twigs hold leaves. Most of us would call that a calm morning, but if the breeze switches
back and forth while we shoot a group, the potential wind-drift error in our group is 6/10ths of an inch. If we and our rifle are truly capable of the ½-inch groups we
constantly read about on the Internet, then adding an erratic 5-mph breeze to the equation results in a group of 1.1 inches — and we know that nobody EVER shoots groups bigger than
an inch with their pet deer rifle.
I was first introduced to the serious use of wind-flags almost 20 years ago by the Campfire's own Mickey Coleman, a noted accuracy gunsmith. We were at an annual
get-together in West Virginia known as the Groundhog Shoot & Prevaricator's Conference, thrown by Melvin Forbes of New Ultra Light Arms. The site was an 800-acre mountain
farm that had been turned into a private fishing and hunting club by Melvin and a bunch of his friends.
One of the great things about the "lodge" (the old farmhouse) was that the front porch was not only a great place for prevaricating, but was only 200 yards or so from a shooting
range equipped with sturdy benchrests. If you wanted to prove some point, or merely torch off a few rounds, all you had to do was wander down there and start shooting.
Mickey had a benchrest rifle along, and set up 4-5 wind flags between one of the benches and a 100-yard target. The flags weren't just strips of flagging tape, either,
but very sensitive little windmills that spun easily on an axis. He invited me to try his rifle and handloads. I sat down at the bench and Mickey explained how
to track all the flags before shooting. This could be done by keeping both eyes open, even when aiming through the scope.
Now, most of us would have called this a very calm day, but the flags kept spinning in different directions, partly because the range was in a little hollow (or holler, as they
say in West-by-God Virginia). I kept an eye on the flags and started shooting, and for the first few shots the hole in the target "just kept getting darker," as the
benchrest boys put it. By then I thought this was pretty easy, but then one shot ended up a little high and left of the group. It wasn't out by much, but there
was definite chunk of white paper between the original one-hole group and that single flier.
"That third flag gotcha," Mickey said. "It turned to the left while the others turned to the right."
Since then I have never done serious load testing of even an elk rifle without some sort of wind flag, and often two or three. Anything helps, even a strip of flagging
tape hung from your chronograph, but when things get serious I haul out some Sinclair flags that combine a sheet-metal wind vane, a plastic "sunflower" that spins off the front of
the vane, and a strip of flagging tape off the rear of the vane. These will turn in the slightest breeze, and the flagging tape and spinning sunflower provide a very good
idea of relative wind speed.
There's some minor controversy about where to set wind flags, but the consensus is that winds closer to the muzzle make the most difference, since they start working on the
bullet sooner. This is why flagging tape hanging from the chronograph can help a lot. When using two of the Sinclair flags, I put one 10-15 yards in front of
the bench, and the other about 60-70 yards out.
The first technique is to watch the flags for a few minutes to find the prevailing wind "condition." After that you only shoot during that condition. Since
you're not on a time clock, like the shooters at a real benchrest match, you can afford to wait until the condition repeats itself, while benchrest shooters often whack away pretty
rapidly anytime the primary wind condition shows up, since it may not show up again before their time's up.
Even factory rifles will shoot some astounding groups when the shooter is aided by wind flags. Among the varmint rifles in our house is a Remington 700 in .223 Remington
with a heavy chrome-moly barrel and laminated stock. I did perform some accurizing tricks on it shortly after it was purchased from Capital Sports & Western Wear close to
a decade ago, but other than that it is bone-stock.
It proved to be pretty accurate, but I never realized just how accurate until one "calm" morning I took it to the range with some handloads prepared in Redding Competition dies
with all the tricks, including Winchester brass sorted by measuring neck thickness to less than .001" and 50-grain Nosler Ballistic Tips sorted by running them over one of
Vern Juenke's Bullet Concentricity Comparators. The powder charge was 26.0 grains of Ramshot TAC.
I put out two Sinclair flags at 15 and 65 yards, and also hung a strip of flagging tape on a fencepost next to the target, and started shooting. In all, eight 5-shot
groups were fired, in order to compare loads from brass that had been totally "uniformed" and loads with brass that had been merely neck-sorted. The groups were all "in
the two's," as the benchresters say, with the smallest just barely two bullet-holes wide.
This was with a factory varmint rifle, common components anybody can buy at a local store, a variable scope set at its maximum 24x, and loading dies in a standard
press. Of course, sorting the bullets really helped, but without the wind flags the test would have been worthless. (Oh, and by the way, the groups shot with
brass that hadn't been "uniformed" were just as small as the others, which is why I quit uniforming brass for hunting loads after that test — except for neck-sorting.)
When testing a centerfire, obviously we should wait between groups to allow the barrel to cool, but when testing rimfires I often use a different technique, whether shooting at
50 or 100 yards. Two or three flags are still used, but I put up a target with four small bullseyes. Instead of waiting for one specific wind condition, I
shoot at one of the bullseyes during one wind condition (say a breeze from straight left), and the other bullseyes during other wind conditions. One condition may even be
dead calm, or as close to it as the flags indicate. That way I can shoot four different groups in a relative hurry, saving time when testing a certain brand of
ammo. The next 4-bull target will then be shot with another brand.
Now, there are some days when I don't feel like setting up wind flags, especially when doing preliminary load work-up on a new big game rifle. At that point I'm only
interested in finding out the basics, and may be running a ladder test on the target to find the general "sweet spot" for the powder charge. For those tests a relatively
calm morning is plenty, because the two important criteria are velocity and a general idea of what powder charges might work. But toward the end of load development, when
things get really serious, sunflowers start sprouting on the range.