.338-378 Weatherby Magnum, JSP, One Cartridge not a Box!
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One Cartridge, not a box: .338-378 Weatherby by Weatherby, “New” production using new brass cases with WEATHERBY 30-378 Wby Mag” Head-Stamp and loaded with a 250 grain Nosler Partition JSP (Jacketed Soft Point) projectile.  Currently 250 grain JSP however projectiles may change without notice due to availability.

History of .338-378 Weatherby Cartridge:            
This massive cartridge was built and factory chambered by Weatherby in 1999, by necking down the huge .378 case to accept .338 projectiles.
This cartridge is loaded with 250 to 300 grain projectiles and produces over 5,000 Foot Pounds of Energy,  with Velocities over 3,000 Feet per Second.

History of the Weatherby cartridge line:
As a young man, in the late 1940's, Roy Weatherby developed an insatiable interest in ballistics and rifle performance.
At a time when many firearms "experts" were promoting large bullets traveling at slow speeds, Roy was experimenting with lighter weight bullets traveling at extremely high velocities.
It was his belief that this combination was ideal in creating the hydrostatic shock needed to kill animals quickly and humanely.
In Roy's mind, there was no other way: speed kills - period.
Roy's initial work began with developing his high powered, magnum cartridges. He developed the .220 Rocket (based on the .220 Swift), and the first Weatherby Magnums - .257, .270 and .300 (based on the .300 H&H Mag.).
From his small operation in South Gate, California, Roy was building his own rifles on virtually any actions he could obtain (FN Mauser, Schultz & Larsen and Mathieus to name a few), as well as offering to rechamber rifles for his newly designed magnum calibers.
Soon, his high powered cartridges began to draw the attention of noted gun writers Jack O'Connor, Elmer Keith and influential such as Sheldon Coleman (of Coleman Company fame). Over the years, Roy would have many "friendly arguments," often conducted
through printed letters and rebuttals in magazines, with the likes of O'Connor, Keith and other firearms experts on the merits of his high velocity cartridges and rifles.
By the mid to late 1950's Weatherby had expanded his line of magnum cartridges to include the .378 Weatherby Magnum (which replaced the .375 Weatherby Magnum) and the .460 (the world's most powerful cartridge, at the time, delivering nearly four tons of muzzle energy).
At that time, he was producing his rifles on German FN Mauser and Czechoslovakian Brevex Magnum Mauser actions.
Later, in 1957, he would develop a new action - originally designated the Model 58 (later to become the legendary Mark V) - specifically designed to handle the magnum loads of his increasingly popular cartridges. Resource :1995 Weatherby Catalog Roy E. Weatherby Sr., Firearms Innovator, 77, AP Published: April 10.
AP Published: April 10, 1988
LEAD: Roy E. Weatherby Sr., a leading authority on ballistics who was the creator of the famed Weatherby rifle favored by big-game
hunters, died Tuesday. He was 77 years old It was Mr. Weatherby's perfection of his theory on high velocity, and the resulting Weatherby Magnum cartridges, that led to the development of the Weatherby rifle.
Roy E. Weatherby Sr., a leading authority on ballistics who was the creator of the famed Weatherby rifle favored by big-game hunters, died Tuesday. He was 77 years old.
It was Mr. Weatherby's perfection of his theory on high velocity, and the resulting Weatherby Magnum cartridges, that led to the development of the Weatherby rifle.

  • Manufacturer: Weatherby

.338-378 Weatherby Magnum, JSP, One Cartridge not a Box!

Price: $24.75
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