.300 Weatherby Magnum

Background

Roy Weatherby already had experience with other custom cartridges such as his own .270 Weatherby Magnum when he created the .300 Weatherby. Like most of his other magnum cartridges, this is based on a blown-out .300 H&H Magnum case, using the signature Weatherby double-radius shoulder. The Weatherby was first introduced in 1944, and the .300 Winchester Magnum was introduced in 1963.

In recent years, Remington, Winchester and Ruger have produced rifles in this caliber, and most major ammunition manufacturers now supply factory loads.

Performance

Historically, Weatherby claimed that this is the most powerful .30 caliber magnum rifle commercially available, but the recently introduced .300 Remington Ultra Magnum, the .300 Norma Magnum and Weatherby's own .30-378 Weatherby Magnum are now more powerful. Of course there are quite a few very large .30 caliber wildcat cartridges.

When comparing the .300 RUM and the .300 Weatherby Magnum, however, there is a difference in factory loadings. Performance data is often listed on the side of the ammunition box for those who wish to do an in-store comparison. On average, Weatherby factory ammo is loaded to higher chamber pressures than Remington or Winchester magnum rounds. The Remington round can be handloaded to equal pressures, and as a consequence, surpass the .300 Weatherby in power.

The .300 Weatherby is commonly used by big-game hunters all over the world.

Use

The SAS captured a rifle chambered in .300 Weatherby Magnum during the Falklands War.

References

• .300 Weatherby Magnum at Accurate Powder Cartridge dimensions.

References

1. [https://web.archive.org/web/20080517061230/http://www.weatherby.com/products/ammo.asp?prd_id=6 .300 Weatherby Magnum page at Weatherby]
2. Bullets, Speer. (2009). "Speer Bullets Reloading Manual #14". Speer.
3. Bullets, Speer. (2009). "Speer Bullets Reloading Manual #14". Speer.
4. [http://www.chuckhawks.com/subscribers/rifle_cartridge_page/300Wby.htm .300 Weatherby by Chuck Hawks (subscription required)]{{subscription required
5. "Weatherby Mk 5, .300 Magnum". Imperial War Museums.