The Ruger Mark IV Rimfire Pistols have the classic look of the Mark III with a simple, one-button takedown for quick and easy field stripping. A recessed button in the back of the frame allows the upper receiver to tilt up and off of the grip frame without the use of tools. The bolt simply slides out of the receiver and the barrel can be properly cleaned from chamber to muzzle. The MKIV includes other significant improvements such as a one-piece grip frame that is precision CNC-machined from a solid piece of aluminum alloy, an ambidextrous manual safety and a redesigned bolt stop for more ergonomic operation. The magazine drops free on release for faster reloads and a redesigned magazine disconnect safety prevents discharge when the magazine has been removed. Internal improvements include changes to the hammer, sear, bolt and firing pin for smoother, more reliable feeding. Specific features vary by model, but the legendary, one-piece barreled receiver and internal cylindrical bolt construction remain the same. The robust design ensures permanent sight-to-barrel alignment and higher accuracy potential than conventional moving-slide designs