How do you judge wind

[dcali]

Ok let’s say to make it simple:
your shooting a 6mm 107 grain with a muzzle velocity 3000fps @1000 yards and you have a consistent true cross wind of 10 mph the full length going right to left
how much would that wind move the bullet to the left @ the target?

This is exactly what a ballistics calculator will tell you. They're very helpful as learning tools. Less so at making real life wind predictions.

 

[gunsandgunsmithing]

Ok let’s say to make it simple:
your shooting a 6mm 107 grain with a muzzle velocity 3000fps @1000 yards and you have a consistent true cross wind of 10 mph the full length going right to left
how much would that wind move the bullet to the left @ the target?

Like Damon said, that's exactly what most any ballistics program assumes and what they will tell you. Problem is, that's not realistic most of the time, to expect a constant wind value for the entire way to the target....even at 100 yards and far less at 1000. It's why bc is important as distance increases too. IME, short, dumpy, low bc bullets almost always outshoot long, high bc bullets...in PERFECT conditions. I'm not sure perfect conditions at 1000 even exist anywhere other than in ballistics programs. Lol!

 

[Bottom Fodder]

Well if I punched it in right it said 8.8 MOA does that sound right?

 

[wjm1000]

Some other things to consider:

The wind closer to the shooter counts more at full value but less and less as the angle changes toward a head or tail wind on the bullet.
Spin drift will cause a left to right wind to increase the height of the bullet and vice versa.
There is a point where angle is more important than speed and vice versa depending on the wind speed.
Wind blows the scope image which must also be factored into the equation.
The sun will also draw the image towards it. As the sun comes over the target, the image rises. Clouds have the opposite effect.

An old 1000 yard benchrest told me when I first started shooting 1000 yard benchrest “ sun up, bullet up, sun down, bullet bullet down”.

 

[gunsandgunsmithing]

Well if I punched it in right it said 8.8 MOA does that sound right?

It's a starting place.

Hypothetically, lets say the first third of the distance is equal to the last two thirds. Now lets also assume we have a 10mph l-r wind for the first third and a 10mph r-l for the 2nd 2/3rds. Now, would you hold in the middle?

 

[Bottom Fodder]

It's a starting place.

Hypothetically, lets say the first third of the distance is equal to the last two thirds. Now lets also assume we have a 10mph l-r wind for the first third and a 10mph r-l for the 2nd 2/3rds. Now, would you hold in the middle?

I would probably hold on the right of 10 ring? But I’m here to learn

 

[Tommie]

All this discussion about wind but no mention of “buck”. Ya know, so and so bullet bucks the wind better than some other bullet. I’d really like someone to explain this bucking thing. What are the physics? Does the bullet lean into the wind to avoid being blown around? Is it related to bust? Like brush busting bullets that don’t change course after plowing through a thicket? Please shed some light!

 

[Rick in Oregon]

"How do I judge wind?"

A picture is worth a thousand words.......



Simple really.

 

[Eagle Six]

The most important wind to me is down range at various distances to target. Near wind at the shooter can be handled by any cheap wind meter for the cost of a box of factory match ammunition. Out there is front is the problem. Where and how I shoot I cannot put out remote wind meters or flags and even if I could often times it would take more than I had, and time that I had to make one shot, and flags would be dependent on an educated guess at best. If we are shooting in the Pacific where the trade winds are steady and predictable over long distance the near wind should work just fine. I've never shot in the Pacific and the time I found the near wind to be steady along a 1000 yards plus distance is when there was no wind and it's been so long since that has happened I cannot remember when! Anyway, that's just my experience.

 

[Bottom Fodder]

From what I’m reading you can have a accurate, rifle and ammo, but if you can’t read the wind your toast at a match

 

[davidjoe]

For all intents and purposes here, a bullet doesn't move sideways unless acted upon. A wind at the first "flag" and zero wind the rest of the way will move the bullet essentially like this


-----------------\_____________________________________>>

The only force still at play after the bullet leaves the cross wind is lateral inertia. For a 10mph wind, that would be worth about 14.6fps opposed to roughly 3000fps of forward inertia. Yes, it will have a new course to it's new poi but I can't see how it will maintain an angular trajectory after the force of wind is no longer acting on it. If you've shot over flags much, you know that it's very common to have several flags going in different directions at the same time and that a steady crosswind is much easier to shoot predictably. So yes, if the bullet is subjected to a steady crosswind for it's entire flight, it may appear angular or curved in it's trajectory,

It didn't draw like I intended but I think it's good enough.

I’m trying to visualize and square this picture of resuming parallel trajectory with how bullets ricochet and skip off water.

If they were self propelled by thrust I’d say yes. But not sure otherwise. Air mass is still mass.

 

[Eagle Six]

For all intents and purposes here, a bullet doesn't move sideways unless acted upon. A wind at the first "flag" and zero wind the rest of the way will move the bullet essentially like this


-----------------\_____________________________________>>

The only force still at play after the bullet leaves the cross wind is lateral inertia. For a 10mph wind, that would be worth about 14.6fps opposed to roughly 3000fps of forward inertia. Yes, it will have a new course to it's new poi but I can't see how it will maintain an angular trajectory after the force of wind is no longer acting on it. If you've shot over flags much, you know that it's very common to have several flags going in different directions at the same time and that a steady crosswind is much easier to shoot predictably. So yes, if the bullet is subjected to a steady crosswind for it's entire flight, it may appear angular or curved in it's trajectory,

It didn't draw like I intended but I think it's good enough.

Does this illustrate a little better?

Birds eye view
Shooter at A
Straight line to target B no wind
Constant wind from the right drifts bullet left to D
At C the wind goes to zero bullet drifts to C then straight line to E

 

[gunsandgunsmithing]

Does this illustrate a little better?

Birds eye view
Shooter at A
Straight line to target B no wind
Constant wind from the right drifts bullet left to D
At C the wind goes to zero bullet drifts to C then straight line to E

View attachment 1462259

Pretty much but would be easier to visualize, to me, if the line between c and d were gone, that shows full drift in a constant wind for the entire flight. But yes, what you have shows that just because you have a blow at the bench, doesn't mean that blow is the same down range and won't have the same amount of deflection as if it were for the full flight.

Would it be much trouble to draw the hypothetical scenario I presented in post 27 above, with line A to B included?? I think that will draw a reasonably close mental image...fwiw.

 

[AWS]

I'm not a wind shooter, nearly seventy years of hunting with rifles the first 40 were in the forest of MN and WI, never had a problem with wind. Here in the west if it's windy I call them in closer and if the tumble.weeds pass me going down the freeway I head into the brush and call them in.real.close.

 

[gunsandgunsmithing]

I'm not a wind shooter, nearly seventy years of hunting with rifles the first 40 were in the forest of MN and WI, never had a problem with wind. Here in the west if it's windy I call them in closer and if the tumble.weeds pass me going down the freeway I head into the brush and call them in.real.close.

It's all relative, depending on distance and your target. A 10mph full crosswind at 300 yards might still be a dead yote but that doesn't mean the bullet didn't drift and it sure wouldn't be in a group or 3/16" dot at that distance.

 

[Eagle Six]

Would it be much trouble to draw the hypothetical scenario I presented in post 27 above, with line A to B included?? I think that will draw a reasonably close mental image...fwiw.

Is this better......

 

[gunsandgunsmithing]

Is this better......

View attachment 1462303

Yes and no.. Read post 27 again, please.

 

[Ned Ludd]

The lateral trajectory of a bullet under the influence of wind will be a curve, not a straight line. If the influence of the wind stops at some point on the way to the intended target, the bullet will continue moving offline on the tangent line to that initial curve at whatever point the wind effect stopped. This is because of bullet rotation, the weathervane effect, and the resultant drag effect that are what actually cause the bullet to move offline under the influence of wind.

 

[Eagle Six]

It's a starting place.

Hypothetically, lets say the first third of the distance is equal to the last two thirds. Now lets also assume we have a 10mph l-r wind for the first third and a 10mph r-l for the 2nd 2/3rds. Now, would you hold in the middle?

Please explain this, "lets say the first third of the distance is equal to the last two thirds".


I can illustrate this, "Now lets also assume we have a 10mph l-r wind for the first third and a 10mph r-l for the 2nd 2/3rds. Now, would you hold in the middle?"

 

[gunsandgunsmithing]

Please explain this, "lets say the first third of the distance is equal to the last two thirds".


I can illustrate this, "Now lets also assume we have a 10mph l-r wind for the first third and a 10mph r-l for the 2nd 2/3rds. Now, would you hold in the middle?"

Let's say it's 300 to the target and in the scenario in post 27, I weighted it to where the first 100 yards is SAME VALUE as the last 200 yards...iow, the drift from the muzzle to 100 should be equal to the drift from 100 to 300. This scenario should yield a dead on hold. Make sense now?