Colt MK IV Series 70

The Colt MK IV Series 70 was an improvement over the M1911A1/Government Model by redesigning the barrel bushing to grip the barrel and give the production gun much improved accuracy. These "collet" bushings worked well but were prone to breaking due to being smaller than the slide diameter, hence the original bushing was made standard once again in in 1988.

Colt's Patent Firearms Mfg. Co. is well known as the original and most recognized maker of 1911-type pistols. Ever since the design's military acceptance in March of 1911, and the beginning of production in January of 1912 Colt has never ceased manufacturing pistols based off the original 1911 design, known in commercial trim as simply the Government Model.

It was seen in the Beverly Hills Cop film series.

Description
The 1911 is generally viewed as one of the finest combat pistols ever designed, and the first successful self-loading pistol. The 1911 was designed by American firearms inventor John Browning and is the oldest service pistol in the world, still used in over 25 nations for over 100 years; it has proven itself to be one of the most popular and timeless handguns ever made. The 1911 has inspired countless copies and similar designs, including the TT-33, SIG-Sauer P226, Browning Hi-Power and CZ-75. The 1911 is widely known for its light, four pound single-action trigger, its slim grip and impeccable ergonomics resulting from an eight round single-stack magazine and its accuracy, which is from a five-inch barrel and locking system.

The 1911 served as the standard-issue sidearm for the United States Armed Forces from 1911 to 1985. It was first used in later stages of the Philippine-American War, and was widely used in World War I, World War II, the Korean War, and the Vietnam War. The M1911 is still carried by some U.S. forces. Its formal designation as of 1940 was Automatic Pistol, Caliber .45, M1911 for the original Model of 1911 or Automatic Pistol, Caliber .45, M1911A1 for the M1911A1, adopted in 1924. The designation changed to Pistol, Caliber .45, Automatic, M1911A1 in the Vietnam era. In total, the United States procured around 2.7 million M1911 and M1911A1 pistols in military contracts during its service life.

The M1911 was replaced by the 9mm Beretta M9 pistol as the standard U.S. sidearm in the early 1990s, but due to its popularity among users, it has not been completely phased out. Modernized derivative variants of the M1911 are still in use by some units of the U.S. Army Special Forces, the U.S. Navy and U.S. Marine Corps. Designed by John Browning, the M1911 is the best-known of his designs to use the short recoil principle in its basic design. The pistol was widely copied, and this operating system rose to become the preeminent type of the 20th century and of nearly all modern centerfire pistols. It is popular with civilian shooters in competitive events such as USPSA, IDPA, International Practical Shooting Confederation, and Bullseye shooting. Compact variants are popular civilian concealed carry weapons, because of the design's inherent slim width and the power of the .45 ACP cartridge.