.240 Weatherby Magnum
Encyclopedia
The .240 Weatherby Magnum was developed in 1968 by Roy Weatherby
. In the development of his own .240in/6 mm
cartridge, Weatherby was significantly influenced by both the success and the limitations of the .244 H&H Magnum
cartridge devised in England by his friend and colleague David Lloyd
. It was the last cartridge to be designed by Roy Weatherby.
used only in Weatherby
rifles. This particular Weatherby case is unique, other than shape, it isn't physically based on other Weatherby cases, having the same rim diameter and similar length as the .30-06. It utilizes the traditional Weatherby rounded double shoulder and a belted case with a length of 2.496in, significantly shorter than the 2.8in case of the .244 H&H Mag.
cartridge. There are of course several faster wildcat rounds available, but the .240 Weatherby outclasses the 6 mm Remington
and the newer .243 WSSM
by about 150 ft/s (45.7 m/s).
While favoured by some varmint hunters, the .240 Weatherby Mag. is not much liked by some reloaders
because the case cannot be formed out of any other brass; one either has to buy Weatherby ammunition or reload used Weatherby cases which tend to be more expensive than those for more common cartridges. With the heavier bullets the .240 Wby. Mag. makes for a good deer hunting cartridge, but it does tend to require a long (>23 inches (584.2 mm).) barrel in order to achieve peak performance.
Roy Weatherby
Roy E. Weatherby was the founder and owner of Weatherby, Inc., an American rifle, shotgun and cartridge manufacturing company set up in 1945. Weatherby created an entire line of custom cartridges, and was one of the people responsible for the industry interest in high-speed cartridges...
. In the development of his own .240in/6 mm
6 mm caliber
This article lists firearm cartridges which have a bullet caliber between and .*Length refers to the cartridge case length.*OAL refers to the overall length of the cartridge.All measurements are in mm .-Pistol cartridges:-.24in :...
cartridge, Weatherby was significantly influenced by both the success and the limitations of the .244 H&H Magnum
.244 H&H Magnum
The .244 Holland & Holland Magnum cartridge was created in 1955 in Great Britain by deerstalker and rifle-maker David Lloyd of Pipewell Hall, Northamptonshire and Glencassley in Sutherland, Scotland, and is not to be confused with the smaller-cased and much milder 6 mm Remington...
cartridge devised in England by his friend and colleague David Lloyd
David Lloyd (riflemaker and sportsman)
David Llewellyn Lloyd was an English deer-stalker, metallurgist, ballistician and sporting rifle maker, of Northamptonshire, England and Glencassley in Sutherland, Scotland. After service in the Royal Air Force in the Second World War, extensive deer stalking, and frequent rifle shooting visits to...
. It was the last cartridge to be designed by Roy Weatherby.
Design
The .240 Weatherby Mag. is a proprietary cartridgeCartridge (firearms)
A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...
used only in 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...
rifles. This particular Weatherby case is unique, other than shape, it isn't physically based on other Weatherby cases, having the same rim diameter and similar length as the .30-06. It utilizes the traditional Weatherby rounded double shoulder and a belted case with a length of 2.496in, significantly shorter than the 2.8in case of the .244 H&H Mag.
Performance
In terms of velocity, the .240 Weatherby is the fastest commercially produced 6 mm6 mm caliber
This article lists firearm cartridges which have a bullet caliber between and .*Length refers to the cartridge case length.*OAL refers to the overall length of the cartridge.All measurements are in mm .-Pistol cartridges:-.24in :...
cartridge. There are of course several faster wildcat rounds available, but the .240 Weatherby outclasses the 6 mm Remington
6 mm Remington
The 6mm Remington was introduced by Remington Arms Company in 1955 as the .244 Remington. It is based on necking down the .257 Roberts. Originally intended as a Varmint and predator cartridge, the .244 was never factory loaded with bullets over 90 grains. Rifles marked .244 Remington have a 1 in ...
and the newer .243 WSSM
.243 WSSM
The 243 Winchester Super Short Magnum or 243 WSSM is a rifle cartridge introduced in 2003. It uses a .300 WSM case shortened and necked down to accept a .243in/6mm diameter bullet, and is a high velocity round based on ballistics design philosophies that are intended to produce a high level of...
by about 150 ft/s (45.7 m/s).
While favoured by some varmint hunters, the .240 Weatherby Mag. is not much liked by some reloaders
Handloading
Handloading or reloading is the process of loading firearm cartridges or shotgun shells by assembling the individual components , rather than purchasing completely assembled, factory-loaded cartridges...
because the case cannot be formed out of any other brass; one either has to buy Weatherby ammunition or reload used Weatherby cases which tend to be more expensive than those for more common cartridges. With the heavier bullets the .240 Wby. Mag. makes for a good deer hunting cartridge, but it does tend to require a long (>23 inches (584.2 mm).) barrel in order to achieve peak performance.
| Muzzle | 100 yd | 200 yd | 300 yd | 400 yd | 500 yd | |
|---|---|---|---|---|---|---|
| Trajectory | 2.8 | 3.5 | 0 | |||
| Energy (ft·lbf) | 2576 | 2183 | 1844 | 1550 | 1294 | 1073 |
| Velocity (ft/s Feet per second The foot per second is a unit of both speed and velocity . It expresses the distance in feet traveled or displaced, divided by the time in seconds... ) |
3406 | 3136 | 2882 | 2642 | 2415 | 2199 |