The 378 Weatherby Magnum was introduced by Roy Weatherby in 1953. It is essentially based on a belted version of the big 416 Rigby case, thus requires an extra-large "magnum" action. Performance is spectacular, with a 270-grain bullet at 3180 feet per second and a 300-grain bullet at 2925, yielding, respectively, 6062 and 5701 foot-pounds of energy. Recoil is also spectacular, both hard and fast, but for those able to withstand it the 378 Weatherby has trajectory similar to a 270 Winchester with the energy of a true big-bore. In its infancy it was probably too fast for the bullets then available, but with modern bullets it is fully adequate for the largest game, yet flat-shooting enough for all hunting conditions. Weatherby has been the primary supplier of both rifles and ammunition.
