This article is about the Colt MK IV Series 70. You may be looking for other similar named Colt firearms.
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.