Ruger has long set the standard for reliable, affordable and accurate .22 LR handguns, beginning with the introduction of the Standard Pistol in 1949. Since then, the Standard Pistol has undergone a series of enhancements with the development of the Mark I, Mark IIâ„¢, Mark IIIâ„¢ and now the Mark IV.â„¢ The Mark IVâ„¢ maintains the classic look of the original but adds a simple, one-button takedown for quick and easy field stripping.