Wind will blow your shots left or right, high or low, depending on the direction the wind is coming from.

Elaborate charts are drawn showing the effect on the bullet of winds from varying directions.

Wind from the left moves the bullet right, wind from the right moves the bullet left, wind from the rear moves the bullet up, wind from the front moves the bullet down.

Many skilled and successful bench shooters use sets of wind flags so that they can "read" the wind. Some of these wind flags are elaborate, with propellers and streamers and wind socks and other startling features. I have used sets of wind flags, generally strips of surveyor's ~1" plastic tape on ~3'-4' wood or steel rods.

I don't know how to hold off in the wind to keep the bullet centered; so I wait until the wind stops if I can, or just guess at the hold off.

I do know that the effect of the wind on the bullet at ranges to 200 yards is much less than many people imagine. I've shot small groups enough in very windy conditions without holding off to say confidently that the wind doesn't effect the bullet all that much. Last Wednesday, 12/20/2006, at the Trail Glades Range in Miami FL, the wind was blowing hard enough to blow a chronograph screen set over, to blow my notebook off the bench twice, and to blow an empty 22 ammunition box off the bench. I shot five 10 shot 100 yard groups with a Ruger MKII scoped 22 pistol, and without holding off for the wind. Groups were 3.85", 3.35", 3.2", 3.325" and 5.1"; an average of 3.77". I shot a C. Sharps 45/70, four 5 shot groups with each of two loads, and again averaged, at 100 yards, 1.8" for one load and 2.15" for the other.

Now we're not talking about breaking any bench rest records here, but the crazy wind does not make the groups crazy, at least at shorter ranges.

When you shoot on a hot day and your rifle barrel gets hot, the heat rising from the barrel can make the target waver around. This is one kind of mirage, and easy to fix. I make a tube out of a target and tape it to the bell of my scope, making the hot air go around the line of sight. I sometimes cut a strip of target as long as from the front scope block or mount to the end of the barrel, about 2" wide, and tape it to the barrel. This also works. Some shooters use a cloth rig between the scope bell and the muzzle. Any of these fixes work.

The other mirage is the waving around and apparent moving of the target caused by the sun and the wind. I've not seen mirage when the sun isn't out, I don't think.

Mirage moves the apparent location of the target, mostly up, so that if you aim and shoot at the target center when the mirage is going on, your bullet hole will be high. There's some left and right displacement going on, but mostly vertical displacement will happen. If there's wind during the mirage, the image can be moved left or right.

When there's a lot of wind, the mirage goes away, or maybe I just don't see it. I think it goes away.

     There's a lot of science talked about during discussions of mirage, explanations of why mirage happens. I don't understand any of this.

If you're at the range on a sunny day with intermittent clouds going overhead, you can watch mirage happen. Set a scoped rifle up on a firm rest, aimed at a sighting dot on the target at 100 yards when there's a cloud keeping the sun off the range. Look through the scope as the cloud leaves and the sun comes out and you'll see the image of the target start to wave around, and your aiming point move up, leaving the scope aimed below the aiming point. When the clouds return you can watch the wavering/boiling go away and the aiming point move down to the cross hair intersection again.

It's often said that when the sun comes out, your shot will go high; and skilled offhand shooters compensate for this effect. I'm not skilled enough for any compensation to matter.

There can and will be mirage regardless of the temperature, there's all the mirage you need at Old Colony in Massachusetts on a zero degree sunny day.

If there's enough wind on a sunny day the mirage seems to go away, but it' may still be there; moving your shots on the paper.

I don't know how to compensate for mirage when shooting from the bench; so I wait till a cloud comes by, watch for the boiling to stop, and then shoot.

I've read several articles on wind and mirage and shooting, and worked at understanding and learning to hold off. I can't hold off to shoot very small groups when it's windy or mirage is heavy. I suspect that learning to hold off is mainly through practice, so that you learn that if you hold off XX inches in a wind that makes the wind flags go YY, then the bullet will be centered.

The sighter target is available to find the point-of-impact (POI) of an aimed shot during wind and/or mirage if there is a time limit for the shots. Many bench rest shooters shoot many more sighters than record shots.