Ammunition designed for .22 caliber firearms, loaded to propel projectiles at velocities below the speed of sound, is categorized as subsonic. This generally translates to a muzzle velocity lower than approximately 1,125 feet per second (343 meters per second) at standard atmospheric conditions. For example, a standard .22 Long Rifle round might travel at 1,200 fps, while its subsonic counterpart might be loaded to achieve 1,050 fps. This reduced velocity alters the round’s characteristics, primarily its sound signature.
Lower velocity cartridges generate a quieter report, often significantly reducing or eliminating the sharp crack associated with supersonic projectiles. This characteristic is advantageous in various applications, including hunting small game where minimizing noise disruption is crucial, or in recreational shooting where noise pollution is a concern. Historically, such rounds have found applications where discreet operation was paramount. The development of specialized loadings and projectiles has further refined the performance and consistency of these lower-velocity rounds.