October 20, 2011
Two Ways to Gauge Wind Speed For Long Shots
By David E. Petzal
“Rifle shooter must break wind first before wind break him.” —Vorislav Djubrotnij, Eastern-bloc shooter of the 1950s, making it all clear.
Recently, I attended a class on how to hit targets at 600 yards and beyond, and came away both impressed and depressed. Of all the factors involved, by far the most uncontrollable and difficult is wind. As an example, a 5 mph breeze, which is just enough to agitate the leaves on the trees, can move a 168-grain .308 bullet 16.1 inches at 600 yards.
Here are two ways to gauge wind speed.
If you can feel a breeze, it’s 3-5 mph.
If the leaves on the trees are moving, 5-8 mph.
If you see loose papers blowing, 8-12 mph.
If small trees are swaying, 12-15 mph.
If your range flag (a good-sized one, with some weight) is hanging at 60 degrees (just a bit out from the pole), 1-3 mph.
Hanging at 45 degrees, 4-7 mph.
Snapping smartly at 90 degrees from the pole, 8-12 mph.
If a cow or an outhouse flies by, you are in a hurricane and should not be shooting.
Also, I’d like to amend something I said during the first season of Gun Nuts. "Watch the wind out where the target is," I said, "not where you are." Turns out I was either half right or half wrong. It’s correct that you can pretty much ignore the wind where you are because the bullet will have its full velocity and will be moved very little, if at all.
The place to look, however, is not at the target but halfway there. If you’re shooting at 500 yards and looking for wind just short of that, it’s of no help because the bullet is at the target for all intents and purposes, and is not going to be pushed. The place to look is 250 yards, because that’s where the mischief will be worked. Makes sense to me.
There is a further amendment. Kenny Jarrett, who has fired more rounds at long range than I have had eggs for breakfast, says that you have to watch the wind between 50 and 75 yards from where you are, and whatever happens beyond that, happens. This runs counter to what I was taught, but as I said, I've seen Kenny shoot.