This specific type of cartridge designates a .22 Winchester Magnum Rimfire round loaded to a velocity below the speed of sound. This generally means a muzzle velocity of less than approximately 1,125 feet per second. Such ammunition typically uses heavier bullets than standard .22 WMR loads, often in the 40-60 grain range, to maintain energy at lower velocities. Heavier projectiles can enhance terminal performance and accuracy at shorter ranges while minimizing noise.
Reduced-velocity .22 WMR cartridges offer several potential advantages. The subsonic characteristic minimizes the loud crack associated with supersonic projectiles, making them suitable for environments where noise reduction is desired, such as pest control or suppressed shooting. The heavier bullet construction can also lead to improved penetration and energy transfer compared to standard high-velocity .22 WMR rounds, particularly at close range. This can be advantageous for hunting small game or varmints. While developed after standard velocity .22 WMR ammunition, subsonic loads have filled a specific niche for shooters valuing quiet operation.
