From Inception to Present
In 1963 Winchester introduced their excellent .300 Magnum cartridge. It soon became their fifth most popular cartridge, with only the .308, .243. .270, & venerable old 30-30 Winchesters achieving more commercial demand. The capable performance of the .300 magnum endeared it to hunters of such large game as elk, and to those long-range precision rifle shooters who wanted an edge over the .308 in both trajectory and resistance to wind deflection.
Enter the Short Mag
In 2001 Winchester made a bold step - they improved upon their universally accepted 300 Magnum by introducing the .300 Winchester Short Magnum (WSM). One of the criticisms leveled against the old 300 Magnum was that due to the long case length, a long action was necessary, adding additional weight to the rifle. Producing 300 Magnum velocities from a cartridge that was designed for short action rifles was no mean feat, but Winchester achieved this aim admirably. The unique geometry of this beltless magnum cartridge delivers the same precise head spacing and high accuracy as cartridges designed for bench rest shooting. Plus, the WSM's "short & fat" cartridge shape delivers a highly efficient powder burn and quicker cycle time via a much shorter and lighter rifle action with a standard magnum bolt face diameter.
The application of this cartridge is primarily focused toward Military and civilian precision riflemen. Law Enforcement's typically shorter-range requirement does not yield the significant advantages, however as distance increases the 300WSM truly excels as a top long-range performer. Having an extended supersonic range, the 300WSM commands a trajectory that is 10½ feet flatter at 1000yds than .308! Whereas the .308 is falling to subsonic levels around the 1000yd mark, the 300WSM still maintains supersonic flight well beyond thanks to it 200fps velocity advantage at that range. The fact that the Short Mag does so with bench rest accuracy and from a standard weight rifle makes it a ballistically superior alternative to 308.
As an intermediate long-range cartridge between .308 and .50 caliber, the .300WSM truly shines. With the addition of our standard muzzle brake, the Short Mag has the same perceived recoil as a .308, and the portability is identical, yet at ranges from 500yds-1000+yds, the 300 Short Magnum offers significantly increased hit potential, greater margin for ranging errors, and increased terminal performance. The .308 has been ballistically outclassed by this remarkable cartridge from Winchester.