I shoot at a
public range where I get to see a wide variety of people practicing many, many
different shooting disciplines. Black powder, military surplus, varmint, high
power hunting rifles - you name it and it’s there. Among the most interesting
are the 22 rimfire benchrest shooters. They shoot bench rest rifles that are
just as technically advanced (and expensive) as the big bore bench resters. If
anyone knows something about shooting in the wind, it’s these guys. Let me
explain.
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"The dual vane Hood wind
flags are more sensitive than standard flags." |
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Instead of
shooting groups at 100 yards, they shoot at a 50 yard American Rimfire
Association (ARA) target that has 25 bulls printed on it in 5 rows of five
each. The center of each bull is only a half inch in diameter and 100 points
is awarded per center punch. Fewer points are scored the further away from the
center that the bullet hits. A perfect score is 2500 points.
“So what’s
the big deal” you might say. They’ve got that big, three thousand dollar 10.5
lb gun sitting on a fancy rest, leather or cordura bags filled with exotic
zircon sand, a state of the art Leupold 45X Competition Series scope sitting
on the top, a click adjustable barrel tuner, and hand selected lots of the
very best Lapua and Eley ammunition. How could you possibly miss? Well folks,
a perfect 2500 score has been only shot ONCE in the history of ARA
competition. Even a target with a score of 2400 is so rare, it has to be sent
to their headquarters to be confirmed. So why aren't perfect scores shot more
often? Wind.
If there was
such a thing as a 50 yard vacuum chamber where a space suited rimfire benchrester could shoot his rifle, all the bullets would very likely go into
the exact same hole with boring regularity. However we live in the real world
where the air is always moving - even when it seems like it isn’t. Another
fact of life in this real world that we live in is that when fired, a 22
bullet is very slow. It’s also very light in weight. Consequently, both of
these characteristics make it very susceptible to every little bit of air
movement that it encounters on the way to our target.
Let me give
you just a few examples of wind situations that I’ve personally observed while
watching bench-rester’s wind flags.
1. The wind is blowing
straight out from the firing line and the propellers on the flags at 5 and 50
yards were spinning rapidly while the propeller on the one at 25 yards was
motionless. How is this possible?
2. All three flags
pointing in radically different directions (very common).
3. Two flags side by side
but set at different heights are pointing in totally different directions.
4. Three flags set in a
row 10’ long, all at the same distance, and all pointing in a different
direction and all indicating different wind speeds.
5. A flag at 25 yards
rotating continuously in a 360 degree circle.
I could go on
for some time with lots of other examples, but the point I’m trying to make is
“There’s no such thing as THE wind.” There are many, many winds between
us and the target, and they’re all doing something different. It’s kind of
like what happens when you stir your coffee. First you move your spoon
clockwise, then counter-clockwise, then back and forth. What’s happening in
your cup is similar to what happens at the range between you and your targets.
There are eddies, swirls, changing currents, cross currents, whirlpools,
surges and who knows what else. It’s also my personal and unproven belief that
there may also actually be moving bubbles of lower or higher barometric
pressure caused by small temperature variations that can cause shots to
unexplainably go high or low.
Anyone who
has shot silhouettes for any length of time knows that air movement affects
our bullets whether it’s the little 22’s or even the big bores. Well, you
might say “I’ll shoot heavy bullets. Surely they won’t be pushed around as
much.” Oh boy, I can’t tell you the number of times when I’ve shot a 44 Mag
revolver with 240 grain bullets in high cross winds where I had to actually
aim at the empty space between the 200 meter targets in order to get a hit on
the adjacent ram . “If big and heavy won’t do it, I’ll go for a really fast
bullet. The wind won’t have enough time to work on it.” That doesn’t work
either. I used to shoot a XP 223 for half scale. My velocities were typically
around 2700 fps and I got lots of 40’s - except when the wind was
blowing. Then you could just forget it.
So what can
we do about air movement? Actually the only thing we can do is to try to
understand it. I say “try” because it’s just totally impossible to understand
it completely. There’s just too much going on at the same time. I know people
who have been shooting big bore benchrest for over 30 years and have been
trying to “dope” the wind all that time. They freely admit they know almost
nothing on the subject - and not for the lack of trying or the amount of money
they’ve thrown at the attempt.
That brings
us to the subject of wind flags. A wind flag is a weather vane type device
that indicates the direction of air movement. They come in two general
configurations i.e. either single vane or double vane. I like the doubles
mainly because I think they look cool and I believe they’re more sensitive.
Both types do a good job however, and they’re about the same in price.
Additionally,
flags are often equipped with a multi-bladed propeller on the front and/or a
broad ribbon type tail on the rear. The purpose of the propeller and/or tail
is to give an indication of air velocity by noting either how fast the
propeller is rotating or how far out the tail is being blown. Most rimfire and
center fire benchresters will have at least three flags set out in a line out
to their targets. Many will use more.
Let me say
right up front, that using wind flags during a handgun silhouette match isn’t
very practical if you use the Creedmoor position. If you could, you’d want a
flag next to each target you’re shooting. You say “Hey, that’s crazy. You
don’t need to do that!” Well ideally, you do. Many, many times I’ve seen
wind flags standing only a few feet apart across in a line actually pointing
in totally different directions, and where one’s propeller is spinning rapidly
and the other’s isn’t moving at all. Even though having a flag for each target
would be ideal, it’s totally impractical.
Another
problem occurs when your knees are drawn up in front of you while in
Creedmoor. They’re likely to block your view of any flags that do happen to be
out there. If not then, they probably will when you move to the next
bank. Most importantly, it’s also very difficult to focus and concentrate on
your sights and to watch the flags simultaneously.
So what CAN
you do with flags? For one, you can use them when developing loads to help
determine the optimum theoretical accuracy of a given combination of
components. Second, and perhaps most important, you can use them try to learn
the general air movement conditions on your range and determine how
they affect bullet placement. This is particularly important when shooting big
bore revolver and 22 rimfire as both are particularly affected by the wind.
Let’s first
take a closer look at wind flags. As mentioned before, flags come in all kinds
of styles and colors. I like the flags made by Hood Custom products
(www.benchrest.com/hoodpress/wind_flags/html).
They’re double vane, meaning there are two vanes set parallel to each other
with a single lead counter weight out front. The purpose of the counter weight
is to balance the front and rear portions of the flag to insure it will turn
smoothly on its pivot point with minimal drag. The vanes on wind flags are
often made of a plastic honeycomb material making them light, strong, and
waterproof. However, I’ve also seen flags made of heavy cardboard and even
sheet aluminum. On the Hood flags, the outside of one vane is colored a very
bright orange and the outside of the other vane is colored a very bright lime
green. The inside of both vanes feature broad vertical black and white
stripes. The orange and green colors make it easy to see what direction the
vane is pointing, while the stripes can help you quantify the direction i.e.
“one stripe into the orange, two stripes into the green, etc.”
As mentioned before, flags can give an indication of wind velocity by
observing a propeller on the front or a tail on the rear. Most people have
both on their flags. These devices are useful, however they have limitations
in that once the velocity of the wind reaches a point, the propellers and
tails get maxed out. In other words, if the propeller is spinning as fast as
its design will allow at 10 mph, if the wind picks up to 11 mph, the propeller
can’t spin any faster. Even if it could, you still wouldn’t be able to tell
any difference - a blur is still a blur.
The same is
true of the tail. If it’s standing straight out at 10 mph, it’ll look exactly
the same at 11 mph. However, with tails, you do have a little more flexibility
in that there is a wide variety of materials that are used that react
differently in the wind. Some tails are made of a strong but light plastic
which works very well in light winds but get maxed out very quickly in higher
wind conditions. Other tails, like on the Hood flags, are made of a heavier
nylon material that isn’t as good in light winds but works well in moderate to
heavier winds. Someone who’s serious about discovering the effects of the wind
would probably be well advised to have two sets of tails (light & heavy) that
you could take on and off your flags to cover all the bases.
Obtaining
your flags is only half of the equation. Now we need something to put them
on. We have two choices. One, there are the classic 3 legged music stands. They’re light
weight, stable, and generally very versatile in that they can be used on
every type of moderately level ground there is. However, they can blow
over if the wind gets up to the 20-25 mph range unless you put a sandbag
on one of the legs. My personal feeling is if the wind is THAT high, it’s
time to go to the club house to get a cup of coffee. The other choice to
mount a flag is a steel stake with a foot rest that you use to push the
stake into the ground. I understand that they’re popular in the East. Out
here in the rocky West, the music stand is a better choice. Interestingly,
both types of stands cost just about the same.
When you buy
your flags, if at all possible, also buy your stands from the same maker to
insure that they’re compatible with each other. Here’s the deal. All music
stands have to be modified by the seller to install a 2-4 inch steel pivot pin
on their tops. A female pivot joint on the flag slips over the stand’s pin and
that’s what the flag swivels around on. Turns out that pins come in two
diameters i.e. 1/4” and 3/16” depending on the stand’s seller. So if your
stand’s pin is one diameter and your flag accepts only another, you’ve got a
problem. Hood doesn’t sell stands, so I bought mine at Sinclair
International. Hood will make their flags to accept either size pin, but first
you need to know what size is on your stands. Also make sure that who ever you
buy your stands from furnishes them with the pins installed. Interestingly,
some don’t. Don’t ask me why not.
After I got
my stands and flags, I went a couple of steps farther to make them more wind
sensitive. This is necessary because there is always a lag between any change
in air movement and the flag’s reaction to that change. We want to minimize
that lag time and make that flag as reactive as much as possible. The first
thing I did was to grind a point onto the top of my stand’s pivot pins with my
little bench grinder. (Originally, the steel pivot pin had a flat top.) I
figured the flag would turn easier in light air if the pin were pointed, and
so it did. I also replaced the optional Hood daisy wheel propeller. The wheel
is large and meaty and probably is very good in really breezy conditions, but
its relatively heavy mass isn’t very sensitive in light winds. My good friend
Bill Racer took a much lighter propeller from an inexpensive K-Mart lawn
ornament and fitted it with a little piece of aluminum tubing in the center of
the hub so it would fit on the shaft of the Hood flag. A piece of brass tubing
would have been better (less friction), but none was available at the time.
Both these simple modifications definitely increased the flag’s
sensitivity. To put the icing on the cake, I then lubed both the pivot pin and
the propeller shaft with a graphite solution. Both “Lock Ease” or “Dri Slide”
work well for this purpose. The flags are now much more reactive than before.
Modifying flags is pretty common and some bench-rester's even will go as far
as to use miniature ball bearings on their propeller shafts.
One thing
about flags though is the fact that they can only give you an indication of
what the air is doing at the precise location where the flag is sited. In
other words, it won’t necessarily tell you how the air is moving just 5 feet
away. This is a major, major limitation. However, there is a simple, very low
cost device that can. I can’t take credit for this idea and unfortunately I
don’t know who to give the credit to. It’s just one of those things that
travel around the grapevine where many ideas are traded but often are never
actually tried. Well, I decided to try it, and found that it works big time.
It’s simply a
string attached to something on the shooting bench ( I use a sandbag.) and
which is stretched out to fifty yards. You’ll probably need a stake or
something similar at 25 yards to prop up the sag in the line at that point.
Tie the far end to a small hook or eye in your target stand or to another
stake. Now take a strip of plastic surveyor’s tape about 18-24” long and tie
it to the string at 5 foot intervals. Surveyor’s tape in various colors can be
purchased at Home Depot for around $3.50 or so. The tape is very thin, very
light, and extremely reactive to the slightest air movement. For lack of a
better term, I call this device a “wind line”. Believe me, with a wind line
out in front of you, you’ll be able to see everything that’s happening
and I guarantee that you’ll be amazed at its complexity. However, be prepared
for jokes and jibes from your friends and fellow shooters when they first see
the wind line. They’ll soon change their tune however when they see the groups
you can shoot using it .
The wind line
is particularly useful in those situations when you know something is
happening out there that the wind flags aren’t telling you i.e. the bullets
aren’t hitting where the flags say they’re supposed to be hitting. Let me give
a quick example: your three flags are motionless indicating there is no air
moving between you and your target. You fire a couple of rounds and your shots
are off - way off. What happened? Obviously, there was moving air out there
that wasn’t being detected by the flags. “How can that be?” you might
ask. Well with a wind line, I’ve observed narrow bands of wind actually moving
between the flags. Obviously, if you don’t know it’s there, you can’t
compensate for it. As I like to say, a wind line actually tells the whole
story about air movement between you and the target.
The wind line
does have a minor disadvantage though. It can be awkward to wind up at the end
of a shooting session. I kind of loop mine up like an extension cord and then
tie things together with a garbage bag twist tie. Conversely, the wind line is
also awkward to unwind as you’re deploying it out to 50 yards. If you’re not
careful, things can get tangled, so take it slow. I probably should look into
coming up with some kind of reel to wrap the wind line around. Another small
disadvantage of a wind line is that under some circumstances, all those
fluttering tails can appear to overlap each other and kind of blur and blend
into each other. Just take a moment or two to look things over, and you’ll
figure out what’s happening. I also use my wind flags simultaneously with my
wind line so if I’m not sure what the wind line is doing, I’ll look at the
flags for a supplemental clue.
So how do you use these various devices? First of all,
let me say this is all art and no science, but there are two basic
methods. One is passive and one is active. The passive method uses
the wind indicators to identify a “condition”. A condition is a set
of circumstances indicating that the air is in a certain state of
being. For instance, in an idealized situation, this might be
when your three flags are pointing all in the same direction
at the same time and the propellers are all rotating at the same
speed. When this occurs, you fire your first shot no matter which
direction the flags are pointing or how fast or slow the air might
be moving - just as long as all three are doing exactly the same
thing simultaneously. After the shot has been fired, the condition
will probably change and the flags will probably be swinging around
in different directions. So now you wait until the original chosen
condition repeats itself. Then you fire your second shot. Since the
second shot was fired under the same set of circumstances as your
first shot, it should be right on top of the first bullet hole - all
other things being equal. Of course they never are exactly. But, if
your second shot is off, you know it’s likely because of the load or
shooter error - not the condition. If you’re really lucky, a
condition may hold long enough for you to fire all your shots. The
chances are though, that you’ll have to just be patient and wait for
your condition to repeat itself. The most desirable condition is of
course using the flags or wind line to indicate that there is no
wind present at the moment. When that precious time occurs, get your
shots off as soon as practical to take advantage of the situation.
The passive method is used primarily for shooting groups when you
don’t care where the group is located on the target board. Your only
concern is the size of the group, not it’s location. If you do care,
then the
passive method would then be used only to indicate when the wind had
stopped moving.
The active method utilizes a wind line or wind flags to observe their
positions and then based on that information, the shooter compensates for the
air movement by changing their aim point. This is very difficult to do and
takes a lot of experience, skill, intuition, and luck. This method is used
when we’re trying to place our shots in a specific place like the center of a
22 shoot off target or the center of a bull. Let me give an simple
example. Say all your three flags indicate that the air is moving from right
to left at a moderate speed. Based on your previous experience, you estimate
that your shot will be blown an inch to the left. Consequently, you hold an
inch to the right to compensate. If you were shooting an ARA benchrest target, you could put a shot
on one of the sighter bulls to get a better idea of how far over the wind
would take your bullet. Of course that’s not an option when shooting
silhouettes. However, with a lot of experience, it is possible to become very
skilled at estimating wind drift.
One last
point on the passive/active methods of using wind indicators, it’s not a case
of using one or the other. Almost all 22 benchresters use both methods during
competitions. In situations when the conditions are constantly changing second
to second during a match, you just can’t wait forever for your favorite
condition to return. You’ve got a time limit to contend with, so you go
active. On the other hand, if the movement of the air stops for a period, you
go passive. The moral of the story here is that you have to be flexible in how
you use either a wind line or flag.
So there is
it. Trying to figure out what air movement is happening at any given moment is
extremely difficult and you need good tools to do it. Then, trying to come up
with a way of dealing with it is even tougher, and the only tool available for
that job is that bowl of Jell-O between our ears. However, if we want to hit
small targets and shoot small groups, we’ve got to become serious students of
good old Mother Nature. Two things about Mother Nature always have to be
remembered though. One - she’s the one in charge, not you. Two - she’s got a
wild sense of humor.
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