Winchester Super Short Magnum

From Wikipedia, the free encyclopedia

Winchester 25 Super Short Magnum cartridge

Winchester Super Short Magnum, or WSSM is a line of cartridges introduced by the U.S. Repeating Arms Company (Winchester Inc'). It is a further development of the Winchester Short Magnum concept utilizing smaller bullets, but still of a high velocity.

In 2003 the first cartridges of this design, the .223 and .243 Winchester Super Short Magnums (WSSM), was introduced. It was designed in partnership with Browning Arms Company and Winchester ammunition.

There are basic advantages inherent to the Short Magnum concept: improved accuracy due to the uniform load density and consistent burn of a short, fat powder column and moderate recoil due to more efficient propellants.

[edit] Advantages

As an example the .25 WSSM can be compared to the .25-06 Remington cartridge which is of similar power to highlight the advantages of the WSSM design principles.

The .25 WSSM case has 11% less volume than the .25-06 which has 14% less powder. So the WSSM design has a smaller case, but holds more propellant.

The .25-06 requires a .30-06 length action, whereas the .25 WSSM case which is almost a full inch shorter, does not require a full (standard) length or magnum length rifle action.

This means that a a rifle chambered for the .25 WSSM rifle will be shorter by two full action sizes (from standard to short to super-short length). The intrinsic accuracy benefits of a short, stiffer action over a long action are well-established principles of rifle design. The resulting rifle is smaller, lighter, more compact, and quicker handling, with essentially nondiscernible recoil effect.