true zero

[cheek9075]

while at a shoot this past weekend i was like always having trouble "reading the wind flag". something that i think i may never master. wind started out light but got a little rough. i know, or think i know that a right to left will push a bullet to the left and high, and a left to right will push right and low.
all day long i could not get it seemed like a left wind i could hold at the 9 or 10 ring at 9 oclock and get the x, but a right wind seemed to always go real high and the the left.
point being that the left wind i was holding at 9 oclock at the 10 ring and hitting the x. but the right wind was always high and to the left.
i fought the wind all day and didnt do to good shooting. a friend that is a record holded to me that my zero may be off causing it to shoot like that, he said the rifle will tell you what to do and how to adjust zero. after thinking it over, i could see how that could effect it. if i was at true zero, a left wind should be low and to the right somewhere around 4 to 5 oclock, a right wind should be high around 10 to 11 oclock, i get that.
that all being said, how do you get a true zero? how do you read what the rifle is telling you?

 

[cclfn]

Jon,

A very dear friend of mine used to say "The wind is our freind" very time I prayed for dead calm. The only thing dead calm is good for is geting your scope zeroed so you know where it shoots without wind. Then the trick is to determine if it is really a left wind or a bit of an angle. A true 9 oclock wind would shoot around four or five oclock and low assuming you have a right hand twist barrel. Your friend may have meant that if your POA is not on the POI in calm conditions it becomes very hard to calulate the affect of the wind. There are some charts made up by some real good shooters that you can copy and take with you to the range. I had one laminated just for the bench when I was shooting this is a good one from TMT Enterprises. http://tmtpages.com/windvector_files/windvector-half.gif
Its all about reading the wind in most shooting games.
Hang in there

 

[RonAKA]

I have seen that drawing before, and I have a little trouble making sense of it. When the wind changes one clock position I see a small incremental change in the POI. However there are two exceptions. When the wind changes from 6 to 7 and from 12 to 1, the POI makes a huge step change in a direction that makes no sense to me. Do you believe that something totally different happens when the wind moves from 6 to 7 and 12 to 1?

The other issue is that I read a book by Harold Vaughn. His calculations show that the head and tail wind component have little affect on trajectory, only the side wind. Also at 100 yards his calculations suggested the lift (right wind) and drop (left wind) effect was about 1/3 of the wind drift. The actual amount depends on the stability factor of the bullet. The more stability(spin) you have the larger the lift and drop effect.

But then again, perhaps I just don't understand all that is going on with the wind...

 

[fdshuster]

And how do you make "corrections" when the wind is coming from three, four, or more directions, at different distances from the target, including different velocities? I've watched the flags at 100 yd, indicating a strong wind from 8:00 (for example), at 2 & 300 they can all be at dead stop, and at 4 & 500 the vanes can look like an airplane propeller at takeoff from the 1:00 to 3:00 positions. I've watched direct head and tail winds moving over uneven ground contours ( bunkers/berms at various distances) pick bullets up for a high hit and pull them down for a low hit. The only times I can make an intelligent decision is when they are steady, and from the same direction, and that condition seldom seems to happen. "The wind is your friend". Not for me it isn't.

 

[cheek9075]

we looked at that diagram you posted above, thats how the conversation got started this past weekend. i just dont see that chart being right, dont what to start anything by saying that.