.30-378 Weatherby Magnum 180gr Hornady Interlock Ammo

Description

The .30-378 Weatherby Magnum holds a unique place in the rifle world as the fastest .30 caliber production cartridge available. Developed from Roy Weatherby's 1959 wildcat design and commercially reintroduced in 1996, this cartridge was built for one purpose: maximum velocity in a .30 caliber platform. That translates to flat shooting, excellent wind-bucking capability, and retained energy at distances where most other cartridges run out of steam.

Ballistics and Long-Range Performance

This load pairs Weatherby's Select ammunition with Hornady's proven Interlock bullet in 180 grains. From the muzzle, you're looking at 3,350 fps with 4,485 ft-lbs of energy. The bullet's impressive .425 ballistic coefficient keeps it slicing through the air with minimal resistance, maintaining trajectory and energy over extended distances. Performance really shines beyond 1,000 yards where the flat trajectory becomes a genuine asset rather than a nice-to-have feature. The cartridge is chambered in rifles with 26-inch barrels or longer to take full advantage of the powder column's potential.

Hornady Interlock Bullet Construction

The Hornady Interlock design uses a raised ring embedded inside the bullet jacket that locks the core and jacket together during expansion. This prevents the kind of core-jacket separation that can happen with conventional cup-and-core bullets, especially at the extreme velocities this cartridge produces. The result is retained mass and energy for deep penetration, controlled expansion, and large, consistent wound channels. The exposed lead tip initiates expansion on impact while the locked construction maintains structural integrity.

Built for Big Game at Distance

This ammunition is engineered for hunters pursuing elk, moose, caribou, and other large North American game where shots may stretch beyond typical hunting ranges. The flat trajectory and energy retention make it particularly suited to open country hunting where wind and distance are real factors. The 180-grain bullet weight sits in the sweet spot for this cartridge, balancing velocity with the mass needed for reliable performance on heavy game. Weatherby loads this round into premium Norma brass casings using clean-burning powders for consistent shot-to-shot performance.