Powerful auto pistol cartridge. Near .41 Magnum energy in semi-auto. Popular for hunting and bear defense.
Type: Pistol
Introduced: 1983, United States
Parent case: None
Standardization: SAAMI
Bullet diameter: 0.4" (10.16 mm)
Case length: 0.992" (25.2 mm)
Overall length: 1.26" (32 mm)
Max pressure: 37,500 PSI
Rim type: Rimless
Primer: Large Pistol
Typical twist rate: 1:16
Muzzle velocity: 1050–1400 fps
Muzzle energy: 450–750 ft-lbs
Effective range: 50 yd
Common bullet weights: 135, 155, 165, 175, 180, 200 gr
Primary use: Hunting, Self Defense, Target
Production status: Active
Also known as: 10x25mm
History: Developed in early 1980s by Jeff Cooper as ideal combat pistol cartridge. FBI adopted in 1989 but withdrew after agents complained of recoil. That failure led to .40 S&W. Cult following remains.
Notable firearms: Glock 20, Colt Delta Elite, S&W 1006
Military use: {"country":"FBI (withdrawn)","years":"1989-1990"}
Similar cartridges: .40 S&W, .357 SIG