.243 WSSM

The .243 Winchester Super Short Magnum (WSSM) is a relatively modern cartridge, developed in the early 2000s as part of Winchester and Browning’s quest to create efficient, high-velocity rounds in a compact form. Introduced in 2003, the .243 WSSM is based on the concept of the short magnum family, using a radically shortened, fat case derived from the .300 WSM but with a much smaller powder capacity tailored for smaller projectiles. The resulting cartridge measures only 2.36 inches in overall length, making it well-suited to short-action rifles. This innovation promised magnum-level performance in a compact platform, which particularly appealed to hunters and shooters interested in lighter, handier rifles without sacrificing ballistic prowess. While the .243 Winchester it’s based on has a storied history dating back to the 1950s, the WSSM variant brought new performance levels through modern case design and propellant capabilities.

For reloaders and hunters, the .243 WSSM’s main application is as a dual-purpose cartridge excelling in both varmint/predator and medium game hunting. Thanks to its high velocity and flat trajectory, it’s ideal for long-range varmint shooting, where precision and minimal bullet drop are critical. Its powerful ballistics make it a practical choice for coyote, fox, and bobcat, as well as prairie dog and groundhog shooting where shots can stretch out to several hundred yards. Moreover, the .243 WSSM is more than capable as a deer cartridge, offering reliable terminal performance for whitetail and mule deer at both typical and extended hunting distances. The short magnum design, combined with modern rifles like the Winchester Model 70 and Browning’s A-Bolt, means shooters benefit from reduced rifle weight and excellent handling in the field, making it a favorite among mobile hunters and youth shooters.

In terms of target species, the .243 WSSM covers a broad spectrum. On the varmint side, light, fast-expanding bullets in the 55–70 grain range make quick work of small game, providing explosive terminal performance and minimal risk of ricochets—crucial for open-country shooting. For medium game, such as deer and antelope, reloaders typically opt for heavier bullets in the 85–100 grain range, favoring controlled expansion or bonded core designs for dependable penetration and energy transfer. While not usually recommended for larger game like elk, some seasoned reloaders have achieved ethical kills with the right bullet construction and placement, but it's universally advised to consider more potent calibers for such pursuits.

Reloaders find the .243 WSSM particularly interesting for its case capacity and pressure limits. The short, fat design allows for rapid powder ignition and consistent pressures, contributing to the accuracy and velocity that make this round stand out. Typical bullet weights for reloading range from 55 to 100 grains, with twist rates of 1:10 or 1:12 accommodating the spectrum well. Muzzle velocities can exceed 4,000 fps with lighter bullets, while 100-grain projectiles can still approach or surpass 3,100 fps, making this one of the fastest commercially available .243-caliber rounds. The case’s short neck does present some challenges with seating longer bullets, a detail seasoned reloaders account for when working up custom loads. Brass availability can sometimes be limited, but good case life and modern reloading components help mitigate these issues, allowing dedicated enthusiasts to enjoy the unique performance envelope the .243 WSSM provides. Ultimately, for reloaders seeking magnum performance in a short-action platform, the .243 WSSM presents a distinctive and high-impact choice for both bench and field use.