.22 Caliber LR Ruger Mk I Pistol
Title: Pistol, Automatic, .22 Cal LR, Mk I, Ruger, US, S/N 154069
Accession #: NHHC 1968-577-D
Circa: 1958
Size: 11 x 5.5
Medium: Metal, Wood
Location: Headquarters Artifact Collection, Naval History and Heritage Command
The Ruger Mk I pistol is a rim fire, blowback operated, semi-automatic that fires .22 caliber long rifle ammunition fed from a 9-round removable box magazine stored in the grip. The design of the pistol is based on the Japanese Type 14 Nambu pistol and was first produced in 1949 by Sturm, Ruger and Company. Initially called the “Standard”, the designation was later changed to the Mk I. The pistol was produced until 1982 when the improved Mk II was introduced. The example shown was manufactured in 1958. The US military procured a significant number of Ruger Mk I pistols for use in marksmanship training. The smaller caliber ammunition was less expensive and could be used on small indoor ranges.
The Ruger Mk I consists of two stamped carbon steel receiver halves welded together with a screwed in, 4.75-inch long tapered barrel. A large ejection port is on the right side of the receiver. The grip panels are hard, black checkered rubber affixed with two screws. Unlike most blow-back operated pistols, the Mk I does not have a movable slide. The bright steel tubular bolt slides within the receiver and is opened by pulling back on the rear portion which protrudes from the receiver. A magazine catch is at the base of the grip adjacent to the magazine well. The long, thin, stamped steel, detachable magazine has a vertical slot on each side of the body, a spring-loaded, bright metal follower set at a sharp angle to the body and a wide, bright metal removable baseplate. The magazine holds nine rounds of .22 caliber long rifle ammunition.
