Winchester's super-short .22 magnum — a fat, stubby case driving .22 bullets to .22-250 velocities in a short-action platform. One of three Winchester Super Short Magnums introduced in 2003. Discontinued after limited commercial success.
Type: Rifle
Introduced: 2003, United States
Parent case: .300 WSM
Standardization: SAAMI
Bullet diameter: 0.224" (5.69 mm)
Case length: 1.67" (42.42 mm)
Overall length: 2.36" (59.94 mm)
Max pressure: 65,000 PSI
Rim type: Rebated
Primer: Large Rifle
Typical twist rate: 1:10
Muzzle velocity: 3600–3850 fps
Muzzle energy: 1583–1819 ft-lbs
Effective range: 300 yd
Common bullet weights: 55, 64 gr
Primary use: Varmint, Target
Production status: Discontinued
Also known as: .223 Winchester Super Short Magnum · 5.56x42mm
History: Introduced in 2003 as part of Winchester's WSSM family for the Browning A-Bolt Short Action. The concept — maximum case capacity in minimum length — produced extremely high velocities but also extreme barrel erosion. Winchester discontinued factory WSSM ammunition around 2018–2019. Remaining rifles and ammunition are collector items.
Notable firearms: Browning A-Bolt WSSM, Winchester Model 70 WSSM
Similar cartridges: .22-250 Remington, .243 WSSM, .223 Remington