From Wikipedia, the free encyclopedia:
“The .257 Weatherby Magnum was introduced as a wildcat during the mid 1940s when Roy Weatherby was building custom rifles around war surplus '03 Springfield and the '98 Mauser actions. It was always his favorite cartridge.
The .257 Weatherby Magnum cartridge case itself a shortened version of the .300 H&H Magnum case necked down to .257 caliber and blown out the full length of the case which then sports a double radius shoulder and shortened to 2.545" with a long neck.
The 257 Weatherby Magnum is an extremely flat-shooting dual-purpose cartridge and is the fastest of all commercially available 25 caliber cartridges, sending a 75-grain (4.9 g) bullet out the muzzle at 3,900 feet per second (1,190 m/s) for varmints and able to send a 115-grain (7.5 g) bullet out the muzzle at 3,400 feet per second (1,040 m/s) for deer sized game. It is well suited for plains hunting and other areas where very long range shooting is expected.”
.257 Weatherby Magnum. (2008, November 4). In Wikipedia, The Free Encyclopedia. Retrieved 17:46, March 17. 2009. from http://en.wikipedia.org/w/index.php?title=.257_Weatherby_Magnum&oldid=249666145