338-378 Weatherby Magnum ammo is a mouthful, but is also a very potent round. The 338-378 Weatherby Magnum began its long and industrious life as many powerful rounds do, as a wildcat cartridge. The round was originally known as the 338-378 Keith Thompson magnum in the 1960's. These men were known for their experimentation into larger calibers with more power.
The 338-378 Weatherby magnum is most useful for long range shooting, and is capable of making extremely long shots and transferring energy into targets. At 500 yards the round is still capable of transferring 2501 foot pounds. The round at 1500 yards will still be capable of supersonic velocity. This gives the round a very potent edge for long range hunting.