Winchester developed their .270 Winchester Short Magnum (WSM) in 2002 to improve upon the performance of the iconic .270 Winchester. They created the cartridge by necking down the case of a .300 Winchester Short Magnum to accept a 0.277 inch bullet. The performance increases that resulted far outshine the .270 Winchester, and in certain configurations, will even match the performance of the .270 Weatherby Magnum.
A few major manufacturers sell a variety of excellent factory loads for the 270 WSM. Winchester sells the cartridge with bullets weighing between 130 and 150 grains that have proven effective for harvesting animals from deer to elk. Several specialty bullets come loaded from the factory including Nosler Partition, Accubond, and Barnes TSX, just to mention a few of the choices. Muzzle velocities for the .270 WSM peak at nearly 3,300 feet per second for the 130 grain bullet, and maintain a respectable 3,100 feet per second for the 150 grain bullet.
The .270 WSM delivers the accuracy required to be a reputable hunting cartridge. Three shot groups commonly spread less than one inch at 100 yards. This is largely due to the shorter, fatter case design that allows for a more even powder burn. The even powder burn makes for greater consistency from shot to shot. An additional benefit of uniform powder burn is the requirement for less powder to achieve desired velocities. This cartridge, with less powder burning more efficiently, generates less felt recoil than similar cartridges.
One more great benefit of the .270 WSM, is that rifles chambered for this cartridge use a short action, like the Winchester Model 70 and the Browning BAR. The rifle, as a result, is lighter and quicker to operate, a nice plus for hunters of smaller stature. Hunters also like that the cartridge works well in barrels of 23 and 24 inch lengths. Combining a short action with a short barrel and lighter stock, made possible due to reduced recoil, the .270 Winchester Short Magnum is a very appealing cartridge.