A high-performance varmint wildcat pushing .224-caliber bullets past 4,000 fps from a .308 Winchester-based case — the fastest practical .22-caliber cartridge outside of experimental rounds.
Type: Rifle
Introduced: 1989, United States
Parent case: .308 Winchester
Standardization: Wildcat
Bullet diameter: 0.224" (5.69 mm)
Case length: 1.765" (44.83 mm)
Overall length: 2.6" (66.04 mm)
Max pressure: 62,000 PSI
Rim type: Rimless
Primer: Large Rifle
Typical twist rate: 1:12
Muzzle velocity: 3900–4200 fps
Muzzle energy: 1690–2145 ft-lbs
Effective range: 400 yd
Common bullet weights: 50, 52, 55 gr
Primary use: Varmint, Target
Production status: Limited
Also known as: .22 Cheetah Mk II · 22 Cheetah
History: Developed around 1989 by Guns & Ammo's Jim Carmichael as an exploration of maximum .22-caliber performance. The Cheetah uses a shortened, blown-out .308 Winchester case with a steep 40-degree shoulder to maximize powder capacity while keeping the overall length manageable in a standard short action. At over 4,000 fps with a 50-grain bullet, it represents the practical velocity ceiling for…
Notable firearms: Custom bolt guns, Remington 700 actions
Similar cartridges: .22-250 Remington, .220 Swift, .22 K-Hornet