The smallest practical centerfire pistol cartridge. Designed for ultra-compact pocket pistols where size matters more than power.
Type: Pistol
Introduced: 1905, Belgium
Parent case: None
Standardization: SAAMI
Bullet diameter: 0.25" (6.35 mm)
Case length: 0.615" (15.61 mm)
Overall length: 0.91" (23.11 mm)
Max pressure: 25,000 PSI
Rim type: Semi-Rimmed
Primer: Small Pistol
Typical twist rate: 1:16
Muzzle velocity: 750–900 fps
Muzzle energy: 62–90 ft-lbs
Effective range: 15 yd
Common bullet weights: 50 gr
Primary use: Concealed Carry, Self-Defense
Production status: Active
Also known as: 6.35mm Browning · 6.35x15.5mmSR
History: Designed by John Browning for the FN Model 1906, the first true pocket pistol. Enabled a new class of ultra-compact concealed carry pistols. Popular among civilians and women's market in the early 20th century.
Notable firearms: FN Model 1906, Colt Model 1908 Vest Pocket, Beretta 950 Jetfire
Similar cartridges: .32 ACP, .22 LR