.338-378 Weatherby Magnum
Encyclopedia
The .338-378 Weatherby Magnum started out as the wildcat cartridge
, .338-378 Keith-Thomson Magnum during the early 1960s. Keith and Thomson are Elmer Keith
and R.W. "Bob" Thomson. The 338-378 Keith-Thomson Magnum is slightly shorter than the .338-378 Weatherby Magnum. However this is only a neck length issue of about eighty-thousandths of an inch. The .338-378 Weatherby Magnum was added to the Weatherby
product line in 1998.
The .338-378 Weatherby Magnum’s parent case is the .378 Weatherby Magnum
. The .338-378 Weatherby Magnum is created by necking down the .378 Weatherby Magnum to 8.59 mm (.338 in) then fire forming
it in the rifle chamber. The .338-378 Weatherby Magnum has a case capacity of about 8.1 g
(125 gr). Bullets commercially available for the .338-378 Weatherby Magnum range from: 11.7 g (180 gr) to 19.4 g (300 gr) in the construction of; boat-tail hollow-point; boat-tail pointed soft; pointed soft point; heavy jacketed pointed soft point; partition; multi-core; truncated solid and monolithic solid.
The .338-378 Weatherby Magnum’s main appeal is long-range shooting. A Weatherby factory cartridge loaded with a 16.2 g (250 gr) hunting bullet, in a rifle with a 71 cm (28 in) barrel will yield a muzzle velocity of 933 m/s (3060 ft/s) and muzzle energy of 7046 J
(5197 ft·lbf). This same bullet will carry a down range velocity to 457 m (500 yd) of 648 m/s (2125 ft/s) and energy of 3391 J (2501 ft · lbf).
A hand loaded .338-378 Weatherby Magnum used for 1000 yd target shooting loaded with a 19.4 g (300 gr) boat-tail hollow point from a rifle with a 71 cm (28 in) target barrel will yield a muzzle velocity of 917 m/s (3010 ft/s), at 914 m (1000 yd) will carry a down range velocity of 590 m/s (1936 ft/s) and at 1372 m (1500 yd) will still be carrying a supersonic
down range velocity of 462 m/s (1517 ft/s).
The .338-378 Weatherby Magnum is appropriate for hunting all game animals on the North American, European and Asian continents. In Africa the 338-378 Weatherby Magnum is appropriate for taking medium and large game.
The free recoil
of the 338-378 Weatherby Magnum from a (11 lb) rifle (including magazine rounds, scope, base and rings) is 73 J (54 ft · lbf) as compared to an average 27 J (20 ft · lbf) from a rifle chambered for .30-06 Springfield
.
The Finnish .338 Lapua Magnum cartridge introduced in 1989 and the American .338 Remington Ultra Magnum
(.338 RUM) cartridge introduced in 2000 are probably the closest currently (2007) commercially available ballistic twins of the .338-378 Weatherby Magnum. The .338 Lapua Magnum is however a rimless
cartridge and the .338 Remington Ultra Magnum is a rebated rim
cartridge.
Wildcat cartridge
A wildcat cartridge, or wildcat, is a custom cartridge for which ammunition and firearms are not mass produced. These cartridges are often created in order to optimize a certain performance characteristic of an existing commercial cartridge.Developing and using wildcat cartridges does not...
, .338-378 Keith-Thomson Magnum during the early 1960s. Keith and Thomson are Elmer Keith
Elmer Keith
Elmer Keith was an Idaho rancher, firearms enthusiast, and author. Keith was instrumental in the development of the first magnum revolver cartridge, the .357 Magnum, as well as the later .44 Magnum and .41 Magnum cartridges.-Personality and life:Keith's trademarks were his cigars, his ten-gallon...
and R.W. "Bob" Thomson. The 338-378 Keith-Thomson Magnum is slightly shorter than the .338-378 Weatherby Magnum. However this is only a neck length issue of about eighty-thousandths of an inch. The .338-378 Weatherby Magnum was added to the Weatherby
Weatherby
Weatherby, Inc. is an American gun manufacturer founded in 1945 by Roy Weatherby. The company is best known for its high-powered magnum cartridges, such as the .257 Weatherby Magnum and the .460 Weatherby Magnum...
product line in 1998.
The .338-378 Weatherby Magnum’s parent case is the .378 Weatherby Magnum
.378 Weatherby Magnum
The .378 Weatherby Magnum was designed by Roy Weatherby in 1953. It was an original belted magnum design with no parent case, inspired by the .416 Rigby and headspacing of the belted .375 H&H Magnum. The 215 magnum rifle primer was developed by Federal specifically for this round. The cartridge can...
. The .338-378 Weatherby Magnum is created by necking down the .378 Weatherby Magnum to 8.59 mm (.338 in) then fire forming
Fire forming
The term fire forming in firearms refers to the process of reshaping a metallic cartridge case to fit a new chamber by firing it within that chamber...
it in the rifle chamber. The .338-378 Weatherby Magnum has a case capacity of about 8.1 g
Gram
The gram is a metric system unit of mass....
(125 gr). Bullets commercially available for the .338-378 Weatherby Magnum range from: 11.7 g (180 gr) to 19.4 g (300 gr) in the construction of; boat-tail hollow-point; boat-tail pointed soft; pointed soft point; heavy jacketed pointed soft point; partition; multi-core; truncated solid and monolithic solid.
The .338-378 Weatherby Magnum’s main appeal is long-range shooting. A Weatherby factory cartridge loaded with a 16.2 g (250 gr) hunting bullet, in a rifle with a 71 cm (28 in) barrel will yield a muzzle velocity of 933 m/s (3060 ft/s) and muzzle energy of 7046 J
Joule
The joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...
(5197 ft·lbf). This same bullet will carry a down range velocity to 457 m (500 yd) of 648 m/s (2125 ft/s) and energy of 3391 J (2501 ft · lbf).
A hand loaded .338-378 Weatherby Magnum used for 1000 yd target shooting loaded with a 19.4 g (300 gr) boat-tail hollow point from a rifle with a 71 cm (28 in) target barrel will yield a muzzle velocity of 917 m/s (3010 ft/s), at 914 m (1000 yd) will carry a down range velocity of 590 m/s (1936 ft/s) and at 1372 m (1500 yd) will still be carrying a supersonic
Supersonic
Supersonic speed is a rate of travel of an object that exceeds the speed of sound . For objects traveling in dry air of a temperature of 20 °C this speed is approximately 343 m/s, 1,125 ft/s, 768 mph or 1,235 km/h. Speeds greater than five times the speed of sound are often...
down range velocity of 462 m/s (1517 ft/s).
The .338-378 Weatherby Magnum is appropriate for hunting all game animals on the North American, European and Asian continents. In Africa the 338-378 Weatherby Magnum is appropriate for taking medium and large game.
The free recoil
Free recoil
This article is about the energy produced by small arms when discharged. For other uses, go to Recoil Free recoil is a vernacular term or jargon for recoil energy...
of the 338-378 Weatherby Magnum from a (11 lb) rifle (including magazine rounds, scope, base and rings) is 73 J (54 ft · lbf) as compared to an average 27 J (20 ft · lbf) from a rifle chambered for .30-06 Springfield
.30-06 Springfield
The .30-06 Springfield cartridge or 7.62×63mm in metric notation, was introduced to the United States Army in 1906 and standardized, and was in use until the 1960s and early 1970s. It replaced the .30-03, 6 mm Lee Navy, and .30 US Army...
.
The Finnish .338 Lapua Magnum cartridge introduced in 1989 and the American .338 Remington Ultra Magnum
.338 Remington Ultra Magnum
The .338 Remington Ultra Magnum is a .338 caliber rifle cartridge introduced by Remington Arms in 2002. It is a beltless, rebated rim cartridge based on the .300 Remington Ultra Magnum case shortened .090" loaded with a .338 caliber bullet...
(.338 RUM) cartridge introduced in 2000 are probably the closest currently (2007) commercially available ballistic twins of the .338-378 Weatherby Magnum. The .338 Lapua Magnum is however a rimless
Rim (firearms)
A rim is an external flange that is machined, cast, molded, stamped or pressed around the bottom of a firearms cartridge. The rim may serve a number of purposes, the most common being as the place for the extractor to engage...
cartridge and the .338 Remington Ultra Magnum is a rebated rim
Rim (firearms)
A rim is an external flange that is machined, cast, molded, stamped or pressed around the bottom of a firearms cartridge. The rim may serve a number of purposes, the most common being as the place for the extractor to engage...
cartridge.