Ruger Mark IV pistols are the latest evolution of Ruger's original 1949 Standard Auto Pistol. Ruger Mark IV improvements include the use of a solid one-piece fully machined grip frame, a simple take-down mechanism for easy disassembly and cleaning, an improved bolt stop leaver, an ambidextrous manual safety, and a drop-free magazine release. The Ruger Mark IV Target Models feature a heavy bull barrel and adjustable sights for target shooting and training. An accurate sighting system features a drilled and tapped receiver for Weaver- or Picatinny-style rail for easy mounting of optics. The Ruger Mark IV uses the same 10-shot magazine as the Ruger Mark III pistol. The Ruger Mark IV pistol is equipped with a magazine disconnect. This device prevents the trigger from being pulled if the magazine is removed from the pistol.