223 Winchester Super Short Magnum 20rd boxes of Rifle Ammo

The 223 Winchester Super Short Magnum (WSSM) was introduced in 2002 as part of Winchester's family of "super short magnums" with very short, fat cases. Based on Winchester's Short Magnum case shortened and necked to 22-caliber, the 223 WSSM has a case length of 1.6701 inches, rim diameter of .535-inch, and base diameter of .5559. Efficiency in the short, fat case which is conducive to accuracy, but actual velocity is similar to the much more popular 22-250: 55-grain bullet at 3850 feet per second; and 64-grain bullet at 3600. Winchester is the only supplier of ammunition, and few production rifles have been so chambered.