Super-short .243-caliber magnum delivering .243 Winchester velocities in a stubby case. Like its siblings, discontinued after limited market acceptance and a reputation for accelerated barrel wear.
Type: Rifle
Introduced: 2003, United States
Parent case: .300 WSM
Standardization: SAAMI
Bullet diameter: 0.243" (6.17 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: 3600–4060 fps
Muzzle energy: 1582–2033 ft-lbs
Effective range: 300 yd
Common bullet weights: 55, 95, 100 gr
Primary use: Varmint, Hunting
Production status: Discontinued
Also known as: .243 Winchester Super Short Magnum
History: Part of Winchester's 2003 WSSM family. The .243 WSSM achieved the highest velocities of the three WSSM cartridges and was arguably the most practical for deer hunting. Factory ammunition was discontinued around 2018–2019 after Browning discontinued the A-Bolt WSSM platform.
Notable firearms: Browning A-Bolt WSSM, Winchester Model 70 WSSM
Similar cartridges: .243 Winchester, .223 WSSM, .25 WSSM