The MP5SD (Schalldampfer — silenced) features an integral sound suppressor that vents propellant gas through ports in the barrel into a suppressor housing, automatically reducing bullet velocity to subsonic levels without requiring subsonic ammunition. The 8.85-inch barrel measurement is to the muzzle cap; the actual bore is ported. This design eliminates the supersonic crack entirely, making the MP5SD the quietest production submachine gun of its era. Type: Rifle Action: Semi-Automatic Caliber: 9mm Capacity: 30 Year introduced: 1974, Germany Weight: 324 oz Overall length: 31.5" Status: Active Military use: Yes Intended use: law_enforcement, military, special_operations, collecting