Thread: Which is the best wind meter for wind estimation

Originally Posted by Savage1

There seems assumption that if the wind has blown the bullet off 1 inch at 100yd it will be 10 inch off at 1000yd without any more interaction from wind after the 100yd. To me this doesn't seem right because that would mean that the bullet would have had its direction of travel changed, I think that it would more likely be blown onto an almost parallel course one inch off its original path, not perfectly parallel but certainly close.

Short answer: The wind changes the direction the projectile is travelling in. It is an angular defection not one parallel to the original projectile path.

Originally Posted by Toby

Wouldn't the projectile slow down more so over time it will blow further? So it wouldn't be moving at 1 inch every 100m it would be more the further it got out

Can’t remember if the projectile slows faster or slower over time. I suspect the projectile slows down slower over time. Yes, the slower the projectile the more the wind will affect its path.

Originally Posted by ebf

fukit, here goes anyway

Damn you… I should never have responded.

Originally Posted by ebf

if you type in 10mph wind from 90 degrees in a ballistics calc like JBM, that means 10mph average, right ?

so 10mph blowing across the entire range the projectile is traveling ?

Yes.

Originally Posted by ebf

so if 10mph right wind gives 1 inch left deflection @ 100m (not actual, just for argument sake), some folks are saying that the deflection @ 1000m will be 10 times the 100m deflection i.e. 10 inches...

This is wrong unless the 10mph wind is only acting between 0m and 100m.

Originally Posted by ebf

but if wind causes a deflection because of sideways pressure on the projectile (like the large ship example mentioned), would the effect not be compounded as opposed to linear ? test it for yourself, to me it looks more linear than compound, so maybe something else is going on ?

While wind is still acting it is compounded. Just about nothing in life is linear.

Originally Posted by ebf

i think the danger is looking at a projectile as if it is a large polystyrene ball, and thinking that the force vectors involved with wind have a similar effect as those of forward velocity and rotational stabilization. now think of a modern hpbt design projectile, with very high forward velocity, high degree of stability due to rotation, and how those forces are working against any deflection due to wind...

You lost me with this but I will offer one little bit of insight – ballistic coefficient.

Originally Posted by ebf

something else to ponder... if you take a "yacht" shape, and put a dowel or mast thru it from top to bottom, exactly in the center. now imagine it pivots on that dowel. put the shape in a stream of flowing water. will the pointy bit (bow) turn upstream or downstream ?

Don’t change the subject

Originally Posted by ebf

a) 10mph right wind between 0 and 500. deflections at 100 and 500 ?

So sticking to the 1” deflection at 100 for a 10mph wind – the deflection is 1” at 100. The deflection at 500 will be more than 15”.

Originally Posted by ebf

b) 10mph right wind between 0 and 100, no wind between 100 and 500. deflections at 100 and 500 ?

So sticking to the 1” deflection at 100 for a 10mph wind – the deflection is 1” at 100. The deflection at 500 will be 5”.

Originally Posted by ebf

c) 10 mph right wind between 0 and 100, no wind between 100 and 400, 10 mph left wind between 400 and 500. deflections at 100 and 500 ?

So sticking to the 1” deflection at 100 for a 10mph wind – the deflection is 1” at 100. The deflection at 500 will be a little less than 4”.

Originally Posted by Sidney

whether the force is short (impact of another ball) or of longer duration (wind on a projectile) the result is the same..

Ouch – no comment



I repeat: damn you all for dragging me into this