The Guns & Ammo Network



Does Wind Move Bullets Vertically?

Wayne fired this group at 480 yards, with a .243. A 3-o’clock breeze gave even VLD bullets some lift with a 3-o’clock hold.

If you shoot into a head-wind, does the bullet slow appreciably and thus strike lower on the target? Well, not unless the head-wind is of hurricane strength and the target is very far off. Fired into still air, a .270 bullet meets a force equal to that imposed on a stationary object by a 2,000-mph gale. A 20-mph breeze is pretty strong, but it adds (or, in the case of a tail-wind, subtracts) just 1 percent to (or from) existing drag. Any resulting vertical displacement of the bullet is very hard to see.

But wind does move bullets vertically – with a little help from spin induced by the rifling. A right-hand twist will give the bullet “spin-drift” to 10 o’clock in wind that drives from 3 to 9 o’clock. That same twist will depress the point of impact in wind moving from 9 to 3 o’clock – you’ll get a 4-o’clock strike. Reverse that rule for left-twist rifling. Vertical shift is of no account when you’re firing a hunting rifle at big game over normal shooting ranges. But it’s a factor at long range when the X-ring or prairie dog’s noggin is tiny even at top-most magnification.

Accomplished marksman David Tubb has researched this phenomenon and come up with a scope reticle calibrated not only to accommodate normal drop and drift, but also spin-drift. The reticle’s horizontal lines appear on a slant, tracking the actual path of the bullet, not the direction of the wind. I’ve used it; it works!

  • John Loveland

    Love RifleShooter great reading

  • Dale Brenner

    How would I go about having the reticule in my 8X32 changed from the BDC to Mr. Tubbs ?

  • Bryan Smith

    Thank you for your article on spin-drift, it helps me understand the change in elevation due to wind drift .

    I did not notice it untile I got out to about 500 yd with my 300 win mag using 180 gr sierra pro hunter bullets.

  • ken

    Great subject! I'm not that familiar with all manuf's but who issues a rifle with LH twist? Or was that just a point/counter-point example?

    Any books with an in-depth study of this?