Ackley Improved version of the .22-250; pushes .224 bullets to near-.220 Swift velocities with better case life; popular among varmint hunters wanting maximum velocity.
Type: Rifle
Introduced: 1955, United States
Parent case: .22-250 Remington
Standardization: Proprietary
Bullet diameter: 0.224" (5.69 mm)
Rim type: Rimless
Primer: Boxer Small Rifle
Production status: Active
Also known as: .22-250 AI
History: The .22-250 AI reshapes the parent .22-250 Remington case with a sharper shoulder angle, increasing powder capacity and adding approximately 100 fps over the standard .22-250. It is fireformed from standard brass and produces less case stretching than the parent, making it a practical wildcat for serious varmint hunters.