7mm Winchester Short Magnum (WSM) (using Sierra bullets)
Date: Sep 16 2022
The 7mm Winchester Short Magnum (WSM) was introduced around 2001 and was based on a .300 WSM case necked to accept .284-inch/7mm bullets. The shoulder had been repositioned to prevent the .300 WSM from inadvertently being chambered and fired in a 7mm WSM rifle. The WSM family of cartridges was designed to function through a .308 Winchester length action, but with a maximum overall length of 2.860 inches they are slightly longer than the .308. Their shorter powder column has the potential to produce low extreme spreads to aid with accuracy and reduce barrel wear.
The 7mm WSM fully equals the performance of the 7mm Remington Magnum with most bullet weights. For example, factory loads generally feature a 140-grain bullet at 3,225 fps, a 150-grain at 3,150 fps and 160-grain at 3,050 fps from a 24-inch barrel. When fired from a Winchester Model 70 with a 24-inch barrel, factory load velocities were typically within 30 to 60 fps of advertised figures. For several reasons, the 7mm WSM has not enjoyed widespread popularity. It is nonetheless a good cartridge that performed well during testing.