While many European and some American revolvers were designed as double-action models throughout the late 19th century, for the first half of the 20th century, all semi-automatic pistols were single-action weapons, requiring the weapon to be carried cocked and loaded with the safety on, or uncocked with an empty chamber (Colt M1911, Mauser C96, Luger P.08, Tokarev TT, Browning Hi-Power). The difference between these weapons and single-action revolvers is that while a single-action revolver requires the user to manually cock the hammer before each firing, a single-action semi-automatic pistol only requires manual cocking for the first shot, after which the slide will reciprocate under recoil to automatically recock the hammer for a next shot, and is thus always cocked and ready unless the user manually "decocks" the hammer, encounters a misfiring cartridge, or pulls the trigger on an empty chamber (for older weapons lacking "last round bolt hold open" feature).