.30-378 Weatherby Magnum
The Weatherby Collection
The .30/378 Weatherby Magnum is the powerhouse of Weatherby's .30 caliber line, or (as far as I know)
any other 30 caliber cartridge.
It was created in 1996 by necking down the 378 Weatherby  Magnum to accepts .30  caliber projectiles.
Current factory loads yield up to 3,450 Feet per Second and Energy up to 4,900 Feet perSecond with 180 to
250 grain projectiles. Very Impressive