The 270 Weatherby Magnum was the first belted magnum created by Roy Weatherby in 1943, based on the.300 H&H Magnum. The cartridge was one of a series of Weatherby Magnums that shared a 2.545" (64.64mm) case length at the time of its introduction. The.270 established a tiny but devoted following, similar to that of the rest of the Weatherby line of cartridges, which has remained stable to this day, despite new developments like the.270WSM.
The 270 Weatherby Magnum is a hard-hitting, powerful, flat-shooting cartridge. The.270 Weatherby has about 200 ft/s faster performance with any bullet weight due to its higher pressure and larger case that holds more power than the.270 Winchester. Despite its distinctive case design, it is not a specialist cartridge, but rather an outstanding all-around medium game cartridge with minimal recoil (for a magnum). It delivers powerful shock for quick killing at ranges of up to 325 yards. Broad wounding lasts around 450 yards, after which wound channels become more commensurate to the calibre.
The 270 Weatherby Magnum is best suited for light to medium games. Using a bullet of sound construction on larger animals such as Elk, a bullet of sound construction can generate broad, quick bleeding wounds and free-flowing exit wounds on game weighing up to 320kg (700lb). The 270 Weatherby Magnum is the preferred calibre. It is adequate for larger game animals.
Regardless of newer inventions, the 270 Weatherby Magnum continues to keep its own as an emphatic killer of light to medium game, and it does so without creating excruciating recoil - two features that will assure its popularity for many years to come.
Following the immediate success of the .300 WSM in 2001, the .270 and 7mm WSM were introduced in 2002. The last of these cartridges, the .325 WSM, was introduced in 2005.
Like its siblings, the .270 WSM has gained a steady following for a variety of reasons. One of the foremost factors in the success of these cartridges has been the reduction in both size and weight of rifles in comparison to traditional magnum chamberings. The .270 WSM has also given fans of the .270 Winchester a cartridge which boasts greatly enhanced performance supported by readily available factory ammunition.
These cartridges have quickly became popular world wide, with a variety of ammunition found in gun stores around the world. The WSM’s have also received a small amount of negative criticism. Poor magazine to chamber feeding and excessive pressures resulting in difficult extraction have been major complaints. Both of these issues have been addressed at a design level. The most recent of complaints has been the cost of ammunition, ever rising due to metal market demands in developing nations.
The .270 WSM is the third in what is now called the trio of .270 (.277”) caliber commercial cartridges. These include the .270 Winchester, .270 WSM and the .270 Weatherby Magnum.
The .270 WSM sits roughly halfway between the .270 Winchester and .270 Weatherby Magnum in power. Hand loads and more especially the Hornady Light Magnum loads for the .270 Winchester can come close to .270 WSM velocities however, the WSM is able to achieve its goal velocities with relative ease.
Firing 130 grain bullets at between 3250fps and 3300fps, the .270 WSM is capable of delivering high shock for impressively fast killing out to ranges of around 300 yards along with clean but sometimes slightly delayed killing out to 400 yards. After approximately 500 yards, wound channels become proportionate to the expanded bullet.
With heavier 150 grain bullets driven at 3150fps, the increase in BC produces the same killing performance over varying ranges as the lighter 130 grain bullet weight. The .277 caliber absolutely shines when loaded with 150 grain bullets to 3000fps and faster, producing fast kills and deep penetration on a huge variety of game. By the same token, the .270 WSM is not so powerful as to push 150 grain bullets up into the 3200-3300fps ultra velocity range. Ultra velocity can, if the projectile is not designed to operate as such, cause excessive stress to projectiles at close to moderate range impact velocities with a seemingly unusual drop in killing performance. The WSM avoids this problem to a larger degree.
