[Erno86]

Vertical Deflection --- Head winds tend to slow the bullet because of added air resistance and the resultant drag. This is why the point of impact is lower. Tail winds cause just the opposite, thus making point of impact higher. This is called vertical deflection and is not as pronounced as horizontal wind deflection. At 1,000 yards a .30-caliber match bullet will have about a 1/2 minute vertical deflection up with a 10-mph tail wind.

With a 10-mph head wind, the deflection will be about 1/2 minute down. A half-value head or tail wind will be about 1/4 minute deflection. There isn't any set formula or system to help figure vertical deflection, and most shooters don't even consider it. Sierra Bullets' ballistic computer program gives all the vertical deflections, even with the oblique wind angles. If you want exact figures for all ranges and wind angles, this program is the only way to go.

Quotes from the book: Dead On, Authors -- Tony M. Noblitt and Warren Gabrilska, Paladin Press