The blow forward system has only bee used on three commercially-produced firearms: the Schwarzlose 1908, Hino-Komuro, and Mannlicher 1894 (The SIG AK-53 uses a forward barrel movement, but in conjunction with a locked breech). It offers a simple system with a theoretical extra margin of safety because the side cannot come backward off the gun, but at the cost of substantially increased felt recoil. Once the blowback system was out of patent protection, there was no convincing reason to use the blow forward mechanism.