Colt Officer's ACP

The Colt Officer's ACP or Colt Officer's Model is a single-action, semi-automatic, magazine-fed, and recoil-operated handgun based on the John M. Browning designed M1911. It was introduced in 1985 as a response from Colt to numerous aftermarket companies making smaller versions of the M1911 pistol.

History
In 1975, Rock Island Arsenal developed a compact 1911 it called the "General Officer's Model Pistol" for issue to general officers of the US Army and Air Force, but the pistol was unavailable for sale to the general public. The following year, Pat Yates of Detonics had introduced his compact "Combat Master", a chopped down 1911, with 3.5" barrel and a shortened grip frame. Seeing the popularity of these compact pistols, other pistolsmiths began offering similar conversions on customers' 1911s.

In 1985, Colt developed their own in-house version and named it the "Colt Officer's ACP", the following year they introduced a lighter version with an aluminium frame known as the Lightweight Officer's ACP which weighed 10 ounces less (24 ounces). When Colt introduced the 1991 platform (a parkerized version of the 1911, with the series 80 firing pin safety) it included a pistol of the same dimensions as the Officer's ACP. The "C.C.O." or "Concealed Carry Officer's" pistol mated the longer slide and barrel assembly of the stainless-steel Colt Commander with the frame of the blued Lightweight Officer's ACP.

Although praised for its compact size, the Colt Officer's ACP has drawn criticism for being finicky with ammunition and the sharp recoil from the short barrel. Firearms Author, Frank James, writes that the decreased velocity from the shorter barrel causes performance of the round to be less than optimal when used in a defensive situation.

Reliability and accuracy can be improved through modifications such as replacing the stock barrel bushing with an aftermarket part and judiciously honing the hammer and sear. Beyond trigger work, more sophisticated modifications include replacing the stock hammer and sear with lightweight components, installing a high quality spring set and beveling the inside of the ejection port.