WSSMs: Bum Rap?

The three cartridges of the Winchester Super Short Magnum family have created an entirely new category of centerfire rifle ammunition, and an entirely new subject for centerfire rifle hunters to argue about. Winchester asserts that the high efficiency of the short, fat WSSM case design improves the interior ballistics of the cartridge by exposing more propellant surface area to the primer and making ignition more consistent. Plus, the beltless case allows headspacing off the shoulder, which provides better centering of the bullet in the chamber.

And even though equal to or slightly greater in velocity and energy than longer cartridges of the same calibers, WSSMs offer more moderate recoil because of the increased efficiency of the propellants. Moreover, the new super-short receiver design of the Browning and Winchester rifles made specifically for the WSSM case improves accuracy potential by providing a stiff, less flexible action.

All of which would seem to point to highly popular cartridges in the making, yet questions erupted immediately upon the announcement of the .223 WSSM and .243 WSSM in 2003, even before any of the ammunition or production-run rifles were available in the market.

Concerns were expressed that the extreme velocity levels claimed for these lightweight small-caliber bullets would burn out a bore within a couple hundred rounds, much more quickly than existing speedy small bores such as the .22-250.

WSSM pressures were cited as way too extreme for handloading at anything close to factory-claimed velocities, which would keep them at the real-world performance levels of already-proven, less-erosive smallbore varmint and hunting loads. Initial accuracy reports with preliminary ammo samples and prototype rifles were less than stellar.

The reception for the WSSMs has been lukewarm at best, and questions still swirl: Are the WSSMs much more destructive of barrel bores than previous comparable caliber cartridges? Are the WSSMs capable of precision accuracy at velocity levels higher than comparable caliber cartridges? Do the WSSMs offer sufficiently improved ballistic and handling performance characteristics in comparison to comparable caliber cartridges to justify their existence?

Winchester currently offers the .223 WSSM in a 55-grain Ballistic Silvertip (BST) at 3,850 fps in the Supreme line and a 55-grain pointed softpoint at 3,850 fps, or a 64-grain Power Point at 3,600 fps in the Super-X line. These figures compare to 3,680 fps for a 55-grain bullet in Winchester's .22-250 loading and 3,090 fps for the 64-grain bullet in Winchester's Supreme .223 Rem. Power Point loading.

The .243 WSSM is available in a 55-grain BST at a fast 4,060 fps and in a 95-grain BST at 3, 250 fps in the Winchester Supreme line, plus a 100-grain Power Point loading at 3,110 fps in the Super-X line. By comparison, Winchester's conventional .243 Win. loads clock 3,910 fps with the 55-grain BST, 3,100 with the 95-grain BST and 3,090 fps for the 100-grain Power Point Plus.

The .243 caliber .240 Wby. Mag. as factory-loaded with the same 95-grain BST by Weatherby is catalog-rated at 3,420 fps.