Cougar 8000 series pistols are recoil operated, locked breech semi-automatic pistols. These pistols use relatively rare rotating barrel locking system, in which the barrel rotates on recoil to unlock itself from the slide. The rotating motion of the barrel is controlled by the stud on its bottom, which follows the cam track in the steel frame insert. To decrease peak recoil and stress to the frame, the insert is mounted on the recoil spring and is buffered. The frame is made from lightweight aluminum alloy. The basic version of the Cougar pistol is the F model, with double action trigger with exposed hammer, and ambidextrous safety/decocker levers, located on the slide. Alternative is D version, which is double action only, and thus have spurless hammer and no safety/decocker levers. Cougar pistols use double-stack magazines in 9 mm, .357 SIG and .40 caliber models, and single stack magazines in .45 caliber models.