Of the many cartridges developed by Roy Weatherby, the .257 Magnum was his favorite. Many other hunters have felt the same way down through the decades. Based on annual sales of the various Weatherby cartridges, the .30-378 Magnum is in first place followed by the .300 Magnum, .257 Magnum, .270 Magnum, and 7mm Magnum. Weatherby developed his big .257 in 1944, but before settling on the cartridge we know today, he experimented with .25-caliber cartridges on various cases.

Had the slow-burning powders being produced today been available back then, Weatherby would most likely have stuck with the full-length Holland & Holland case. But since IMR-4350 was the slowest burning powder available, he chose to shorten it to slightly over 21/2 inches. Two other Weatherby cartridges, the .270 Magnum and 7mm Magnum, share that same case.

Like all belted magnums introduced by Weatherby, the .257 Magnum has the familiar double-radius shoulder. As popular opinion once had it, that type of shoulder had certain magical properties that caused propellant gas to flow more efficiently from cartridge case to rifle barrel. Those of us who knew Roy know why he chose a shoulder of such unusual shape: He chose it because he knew it would not be easy for every shade-tree chamber reamer grinder in America to duplicate.

Through the years Roy used the speedy cartridge quite successfully on game as large as moose and elk, and even the mighty Cape buffalo fell with one shot during one of Roy's many trips to Africa. Declaring war on something as big and potentially nasty as a Cape buffalo with a 100-grain bullet was not something he recommended to others, and Roy did it just once to prove to himself that it could be done.

The .257 Weatherby Magnum has long been popular among other big-game hunters as well, and one has only to read the many customer testimonials published in Weatherby catalogs dating back to the first one in October 1945 to see just how many fans it has had through the years. Roy's son Ed, who now runs the company, used the .257 Magnum to take a variety of antelope on his first African safari. The list of .257 Weatherby Magnum fans goes on and on.

It is doubtful that many hunters today would use the .257 Weatherby on game as large and as potentially dangerous as brown bear and polar bear, but hunters of yesteryear did it without hesitation. One thing that made the .257 Magnum so effective on big game was the fact that Weatherby was quick to realize most bullets available in the old days were too soft to withstand the tremendous impact velocities delivered by his super-speedy cartridge.

This prompted him to begin offering ammunition loaded with Nosler Partition bullets as early as the 1960s. Doing so made Weatherby the first to offer premium-grade ammunition loaded with what is now often described as controlled-expansion bullets, and I am sure it is the primary reason hunters were able to use the .257 Magnum so successfully on such a variety of game around the world. Back then, two Nosler bullets were offered: a 100-grain Partition at 3555 fps and a 115-grain Partition at 3300 fps. The 100-grain bullet was always Roy's favorite, and since he promoted it at the drop of a hat, I suspect it was also the most popular weight among his many customers who hunted with the .257 Magnum.