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.

[3] In terms of velocity, the .240 Weatherby Magnum was once the fastest commercially produced 6 mm cartridge.

[4] However, the lightweight .243 WSSM 55gr Ballistic Silvertip now outpaces Weatherby's offerings according to some.

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.

makes for a good deer hunting cartridge, but it does tend to require a long (>23 inches (580 mm).)