The H&K P9S is a double-action, semi-automatic pistol known for its accuracy and unique features. It uses a roller-delayed blowback system, similar to the one used in the G3 rifle and MP5 submachine gun, which allows for a fixed barrel and a reliable mechanism. It was one of the first pistols to employ polygonal rifling, which helps to achieve greater accuracy and less friction. The P9S is a direct evolution of the H&K P9, featuring a double-action trigger and other innovative features.
