“To minimize wind drift, use a heavier bullet.”
You’ve probably heard that for most of your shooting life. Sorry, it’s wrong. The correct answer is “Use a higher B.C. bullet.”
Ballistic Coefficient (BC) is a scoring system that ranks a projectile’s ability to fly efficiently through the air. Any bullet’s BC score is a combination of its density (lead has a higher B.C. than copper, for instance) and its form or shape.
A long, sleek, sharply pointed bullet resists air drag better than a short, rough, flat-nosed one. A skinny bullet pushes less air than a fat one. Just think about hunching over while pedaling a bicycle to minimize air drag.
So, while a heavier bullet does increase BC and should decrease drag and thus wind drift, its shape can blunt this advantage. A classic example is a boat-tail spire point and a flat nose bullet fired from a .30-06 Springfield.
Let’s say you’ve been shooting a 150-grain Hornady InterBond (BC of .415) at 2,900 fps. A 10 mph right-angle wind will deflect that bullet 3.5 inches at 200 yards and 7.6 inches at 300 yards.
To minimize that you decide to follow the sage, old advice and shoot a heavier bullet. You select the 180-grain Hornady Round Nose (BC of .241), which your rifle throws at 2,700 fps. That 10 mph right angle breeze redirects this slug 7 inches off target at 200 yards and a whopping 15.5 inches off at 300 yards.
So much for the heavier bullet, right? Well, wait a minute. Shoot Hornady’s 180-grain InterBond (BC of .480) instead of the round nose and watch what happens: 200-yard wind drift is just 3.3 inches and 300 yard deflection is only 7 inches. Not a huge improvement over the 150-grain, but at least it’s an improvement.
So, there is some legitimacy to the old claim that you can minimize wind drift by shooting a heavier bullet. Just make sure that heavier bullet has a higher BC—and drive it as fast as your rifle safely allows.
Just remember this: A heavier bullet will drift less in the wind only if it also has a higher BC, and form or shape is a big part of B.C. The combination of highest velocity and highest BC minimizes wind deflection in all calibers.