I was reading a book and came across a chart of wind drift for typical .308 match ammo at different range and different wind speed/angle. Then all of a sudden it struck me : "I don't know how to calculate wind drift of a given bullet and given muzzle velocity!"

In the field or long range matches this is going to be important, I appreciate any info.

Pyrotek

Pyrotek, Any of the good Reloading books have wind drift info. If you are a serious long range shooter you need a wind "spedometer". Most people over estimate the wind. You can get one from
www.sinclairint.com

There are numerous ballistic programs that can give you the data you are searching for. The ones I have tested seem to be quite reliable. Here is a Swedish one. Don't worry, it is also available in english. Besides the trajectory estimating function, there are some other functions that are quite nice to play with on those dark winter nights.

www.robsoft.nu

Please inform me if I'm violating the rules by presenting this link. In that case I'll remove it instantly.

These guys got it backwards. shoot your bullet. go to target. measure the horizontal error. that is how much drift you have.

IF you want a better way, go to the Norma ballistics website and play with the nomograms there.

http://www.norma.cc./htm_files/javapagee.htm

Everything you need to know for free.

for example, I just loaded 308 165 grain bullet.

at 200 yards with a 29.9 mph crosswind, it will drift 12 inches.

plug in your speed and bullet weight adn distance and angle, and it will show the drift.

When I opened robsoft, I got a page under construction, and then a nice worksheet,but no place to enter wind speed ro direction.

The Norma page shows you effect of wind drift instantly for each distance and direction you ask, for any wind speed up to 29.9 mph.

to each his own...

Easy rule of thumb for a close guestimate.

With a 308 Win class rifle use 1 MOA for each 10mph of full value wind but begin compensation at 200 yards.

10 mph wind, 90 degrees to flight path, 300 yards...adjust 2 MOA on windage dial, 10 mph 500 yards...4 MOA.

(I generally shoot only 168 and 175 Sierra MKs but this should be sufficiently close for other rounds in this category.)

Jameister-great site - that Norma ballistics chart works great.Thanks.