Does weather affect the trajectory of a .270 WSM bullet?

Weather Factors

Wind, humidity, and temperature can significantly impact the trajectory of a .270 WSM bullet. A 5mph crosswind can deflect a bullet by up to 1.5 inches at 100 yards, and a 10mph headwind can reduce the bullet’s velocity by 50-60 fps. To compensate, use a wind deflection chart or consult a ballistic calculator.

Ballistic Coefficient and Range

The .270 WSM bullet’s ballistic coefficient is around 0.475, which means it will experience more drop and drift than a higher-BC bullet like the .300 Win Mag. At 400 yards, a .270 WSM bullet will drop 24 inches and drift 12 inches with a 10mph crosswind. To mitigate this, use a high-quality scope with a BDC reticle and adjust for wind deflection.

Hunting in Inclement Weather

When hunting elk and deer in windy or rainy conditions, use a heavier-for-caliber bullet like the 130gr or 140gr to maintain kinetic energy and penetration. Aim for 1.5-2 inches high at 200 yards to compensate for wind deflection and bullet drop. Use a rangefinder to accurately measure distances and adjust for wind deflection.