Physical wind deflection Vs book value

[peterb]

There has been quite a debate on reading wind which will no doubt go on forever, but I am trying to work out some thing on a tangent to the debate.

I am using a 308 remington Accutip 165 grain round and have found (whilst building my own Data - Flash card) that the bullet drop varies a bit from the actual book values given by Remington, which I would expect.
Please don't chastise me for using these rounds 'cos they are about the best I can find around here.
What I would like to know is if the actual physical wind effect on the projectile will vary from the book data as well.
I had a situation recently where book data gave me around 36" for a particular wind speed and it turned out to be 50 odd inches instead. This is not too say that I misread the wind, but I could hardly feel it on my face and classed it as more of a drift than a wind which was also stable.(I said about 5mph)
The altitude here is about 240 metres which is roughly 800 feet above sea level, dunno if that makes a difference as well ?
So, continuing, are these ballistic tables which are supplied by the ammunition companies calculated at sea level ?

Cheers,

Pete.

 

[Mikecr]

Ballistic tables in a book are no better than reloading criteria in a book..
There are just too many local variables unaccounted for.

Get ballistic software, and calibrate it to your conditions.
That's my advice.

 

[davewilson]

most of the long range shooting that i've done is across valleys between 2 mountains here in Pa. i get a wind reading from my Kestrel and then 2-2.5x it to come up with a correction for the wind. reason being it's always more out in the valley than it is on the mountain side. unless i'm very exposed on a cliff type rock, this seems to work fairly well for me.