 Introduced in 1950, the MK I Target model was basically the same as the Standard pistol, except that it boasted a barrel, adjustable target style trigger, a “Micro” adjustable rear sight, and a front sight blade undercut to reduce glare.In 1952 a barreled version of the MK I Target was added to the lineup, but manufactured only through 1957, making it a collectible rarity today.A heavy bull barreled version of the MK I Target became available in 1963, eventually becoming the most popular length for Ruger Target MK pistols.