The .22-243 Winchester is a varmint wildcat formed by necking the .243 Winchester case down to accept .224" bullets. The increased case capacity over the .22-250 Remington produces velocities in excess of 4,000 fps with 52-55 grain bullets, pushing the limits of useful .22-caliber centerfire performance. It is used by competitive benchrest and varmint hunters seeking maximum velocity and flat trajectory without moving to .224" cartridges on larger parent cases.
Type: Wildcat
Introduced: 1958, United States
Parent case: .243 Winchester
Standardization: None
Bullet diameter: 0.224" (5.69 mm)
Case length: 1.945" (49.4 mm)
Overall length: 2.71" (68.83 mm)
Max pressure: 25,000 PSI
Rim type: Rimless
Primer: Large Rifle
Typical twist rate: 1:10
Muzzle velocity: 3900–4200 fps
Muzzle energy: 1689–2155 ft-lbs
Effective range: 300 yd
Common bullet weights: 50, 52, 55 gr
Primary use: varmint_hunting, benchrest_competition
Production status: Obsolete
Also known as: 22-243 Win · .22-243
History: The .243 Winchester case has proven to be a versatile parent for multiple wildcats given its large case capacity and wide availability. The .22-243 emerged in the late 1950s as the .243 Winchester itself was being introduced, with wildcatters immediately seeing the potential of necking it down. Barrel life is shorter than milder .22 centerfires, and throat erosion is rapid at these velocities,…
Notable firearms: Custom bolt-action varmint rifles