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