As of 05/07/2023 this cartridge is not being produced by Weatherby. Obsolete!
One Cartridge, not a box: .375 Weatherby by Weatherby, “OLDER” production using (then) new brass cases with “ WEATHERBY 375 MAGNUM” Head-Stamp and loaded with a 300 grain JSP (Jacketed Soft Point) projectile. Excellent to near mint, no dents, no corrosion, nice patina.
History of .375 Weatherby Magnum Cartridge:
The 375 Weatherby Magnum was introduced in 1944 as an improved version of the famous .375 H&H cartridge, blown out to a straighter case to increased powder capacity to produce 200 feet per second more in velocity then the 375 H&H.
It was dropped from the line after the introduction of the .378 in 1953, and was obsolete and a high priced collectible for many years until it was reintroduced in late 2005.
A 220 to to 300 grain projectile traveling at 2,650 to 3,100 Feet per second to produce up to 5,350 foot pounds of energy per square inch.
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, 1988LEAD:
Roy E. Weatherby Sr., a leading authority on ballistics who was the creator of the famed Weatherby rifle favored by big-gamehunters, 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.
