# M1911 pistol

The Colt M1911 (also known as 1911, Colt 1911, Colt .45, or Colt Government in the case of Colt-produced models) is a single-action, recoil-operated, semi-automatic pistol chambered for the .45 ACP cartridge.

## History
### Early history and adaptations

The M1911 pistol originated in the late 1890s as the result of a search for a suitable self-loading (or semi-automatic) pistol to replace the variety of revolvers in service at the time.
The United States was adopting new firearms at a phenomenal rate; several new pistols and two all-new service rifles (M1892/96/98 Krag and M1895 Navy Lee), as well as a series of revolvers by Colt and Smith & Wesson for the Army and Navy, were adopted just in that decade.
The next decade would see a similar pace, including the adoption of several more revolvers and an intensive search for a self-loading pistol that would culminate in the official adoption of the M1911 after the turn of the decade.
Hiram S. Maxim had designed a self-loading rifle in the 1880s, but was preoccupied with machine guns. Nevertheless, the application of his principle of using cartridge energy to reload led to several self-loading pistols in 1896.
The designs caught the attention of various militaries, each of which began programs to find a suitable one for their forces. In the U.S., such a program would lead to a formal test at the turn of the 20th century.
During the end of 1899 and into 1900, a test of self-loading pistols was conducted, including entries from Mauser (C96 "Broomhandle"), Mannlicher (Mannlicher M1894), and Colt (Colt M1900).
This led to a purchase of 1,000 DWM Luger pistols, chambered in 7.65mm Luger. During field trials, these ran into some problems, especially with stopping power. Other governments had made similar complaints. Consequently, DWM produced an enlarged version of the round, the 9×19mm Parabellum with fifty weapons chambered for it tested by the U.S. Army in 1903.
American units fighting Tausūg guerrillas in the Moro Rebellion in Sulu during the Philippine–American War using the then-standard Colt M1892 revolver, .38 Long Colt, found it to be unsuitable for the rigors of jungle warfare, particularly in terms of stopping power, as the Moros had high battle morale and often used drugs to inhibit the sensation of pain.
The U.S. Army briefly reverted to using the M1873 single-action revolver in .45 Colt caliber, which had been standard during the late 19th century; the heavier bullet was found to be more effective against charging tribesmen.
problems prompted the Chief of Ordnance, General William Crozier, to authorize further testing for a new service pistol.
Following the 1904 Thompson-LaGarde pistol round effectiveness tests, Colonel John T. Thompson stated that the new pistol "should not be of less than .45 caliber" and would preferably be semi-automatic in operation.
This led to the 1906 trials of pistols from six firearms manufacturing companies (namely, Colt, Bergmann, Deutsche Waffen- und Munitionsfabriken (DWM), Savage Arms, Knoble, Webley, and White-Merrill).
Of the six designs submitted, three were eliminated early on, leaving only the Savage, Colt, and DWM designs chambered in the new .45 ACP (Automatic Colt Pistol) cartridge. These three still had issues that needed correction, but only Colt and Savage resubmitted their designs.
There is some debate over the reasons for DWM's withdrawal—some say they felt there was bias and that the DWM design was being used primarily as a "whipping boy" for the Savage and Colt pistols, though this does not fit well with the earlier 1900 purchase of the DWM design over the Colt and Steyr entries.
In any case, a series of field tests from 1907 to 1911 were held to decide between the Savage and Colt designs. Both designs were improved between each round of testing, leading up to the final test before adoption.
Among the areas of success for the Colt was a test at the end of 1910 attended by its designer, John Browning. Six thousand rounds were fired from a single pistol over the course of two days. When the gun began to grow hot, it was simply immersed in water to cool it.
The Colt gun passed with no reported malfunctions, while the Savage designs had 37.

### Service history

Following its success in trials, the Colt pistol was formally adopted by the Army on March 29, 1911, when it was designated "Model of 1911", later changed in 1917 to "Model 1911", and then "M1911" in the mid-1920s.
The Director of Civilian Marksmanship began manufacture of M1911 pistols for members of the National Rifle Association of America in August 1912. Approximately 100 pistols stamped "N.R.A." below the serial number were manufactured at Springfield Armory and by Colt.
The M1911 was formally adopted by the U.S. Navy and Marine Corps in 1913. The .45 ACP "Model of 1911 U.S. Army" was used by both U.S. Army Cavalry troops and infantry soldiers during the United States' Punitive Expedition into Mexico against Pancho Villa in 1916.
The M1911 officially replaced a range of revolvers and pistols across branches of the U.S. armed forces, though a number of other designs have seen use in certain niches.

#### Designation changes

The pistol's formal U.S. military designation as of 1940 was Automatic Pistol, Caliber .45, M1911 for the original model adopted in March 1911, and Automatic Pistol, Caliber .45, M1911A1 for the improved M1911A1 model which entered service in 1926.
The designation changed to Pistol, Caliber .45, Automatic, M1911A1 in the Vietnam War era.

#### Replacement

At the end of hostilities the government cancelled all contracts for further production and made use of existing stocks of weapons to equip personnel. Many of these weapons had seen service use, and had to be rebuilt and refinished prior to being issued.
From the mid-1920s to the mid-1950s thousands of 1911s and 1911A1s were refurbished at U.S. arsenals and service depots. These rebuilds consisted of anything from minor inspections to major overhauls.
Pistols that were refurbished at government arsenals will usually be marked on the frame/receiver with the arsenal's initials, such as RIA for Rock Island Armory or SA for Springfield Armory.
By the late 1970s, the M1911A1 was acknowledged to be showing its age.
Under political pressure from Congress to standardize on a single modern pistol design, the U.S. Air Force ran a Joint Service Small Arms Program to select a new semi-automatic pistol using the NATO-standard 9mm Parabellum pistol cartridge.
After trials, the Beretta 92S-1 was chosen. The Army contested this result and subsequently ran its own competition in 1981, the XM9 trials, eventually leading to the official adoption of the Beretta 92F on January 14, 1985.
Despite that, the M1911A1 has never been completely phased out. Modernized derivative variants of the M1911, such as the M45 MEU(SOC) and the M45A1 CQBP, as are still in use by some units of the US Armed Forces.

## Variants

Browning's basic M1911 design has seen very little change throughout its production life.

### Operation

The basic principle of the pistol is recoil operation.
As the expanding combustion gases force the bullet down the barrel, they give reverse momentum to the slide and barrel which are locked together during this portion of the firing cycle. After the bullet has left the barrel, the slide and barrel continue rearward a short distance.
At this point, a link pivots the rear of the barrel down, out of locking recesses in the slide, and the barrel is stopped by making contact with the lower barrel lugs against the frame.
As the slide continues rearward, a claw extractor pulls the spent casing from the firing chamber and an ejector strikes the rear of the case, pivoting the casing out and away from the pistol through the ejection port.
The slide stops its rearward motion then, and is propelled forward again by the recoil spring to strip a fresh cartridge from the magazine and feed it into the firing chamber.
At the forward end of its travel, the slide locks into the barrel and is ready to fire again.
However, if the fired round was the last in the magazine, the slide will lock in the rearward position, which notifies the shooter to reload by ejecting the empty magazine and inserting a loaded magazine, and facilitates (by being rearwards) reloading the chamber, which is accomplished by either pulling the slide back slightly and releasing, or by pushing down on the slide stop, which releases the slide to move forward under spring pressure, strip a fresh cartridge from the magazine, and feed it into the firing chamber.

### Composition

Other than grip screws there are no fasteners of any type in the 1911 design.
The main components of the gun are held in place by the force of the main spring. The pistol can be "field stripped" by partially retracting the slide, removing the slide stop, and removing the barrel bushing.
Full disassembly (and subsequent reassembly) of the pistol to its component parts can be accomplished using several manually removed components as tools to complete the disassembly.

### Safety

The military mandated a grip safety and a manual safety. A grip safety, sear disconnect, slide stop, half cock position, and manual safety (located on the left rear of the frame) are on all standard M1911A1s.
Several companies have developed a firing pin block safety. Colt's 80 series uses a trigger operated one and several other manufacturers, including Kimber and Smith & Wesson, use a Swartz firing-pin safety, which is operated by the grip safety.
Language cautioning against pulling the trigger with the second finger was included in the initial M1911 manual and later manuals up to the 1940s.

### Calibres

In addition to the .45 ACP (Automatic Colt Pistol), M1911 models chambered for .38 Super, 9×19mm Parabellum, 7.65mm Parabellum, 9mm Steyr, .400 Corbon, and other cartridges were offered.
The M1911 was developed from earlier Colt semi-automatic designs, firing rounds such as .38 ACP.

### Interwar changes

Battlefield experience in World War I led to some more small external changes to the M1911, completed in 1924.
The new version received a modified type classification, M1911A1, in 1926 with a stipulation that M1911A1s should have serial numbers higher than 700,000 with lower serial numbers designated M1911.
The M1911A1 changes to the original design consisted of a shorter trigger, cutouts in the frame behind the trigger, an arched mainspring housing, a longer grip safety spur (to prevent hammer bite), a wider front sight, a shortened hammer spur, and simplified grip checkering (eliminating the "Double Diamond" reliefs).
These changes were subtle and largely intended to make the pistol easier to shoot for those with smaller hands. No significant internal changes were made, and parts remained interchangeable between the M1911 and the M1911A1.

## Versions
### Wartime production
#### World War I

The need to greatly expand U.S. military forces and the resultant surge in demand for the firearm in World War I saw the expansion of manufacture to other contractors besides Colt and Springfield Armory, including Remington-UMC and North American Arms Co. of Quebec.
Several other manufacturers were awarded contracts to produce the M1911, including the:
* National Cash Register Company
* Savage Arms
* Caron Brothers Manufacturing of Montreal
* Burroughs Adding Machine Co.
* Winchester Repeating Arms Company
* Lanston Monotype Company
However, the signing of the Armistice resulted in the cancellation of the contracts before any pistols had been produced.

#### World War II

The M1911A1 pistol was produced in very large quantities during the war. About 1.9 million units were procured by the U.S. Government for all forces, production being undertaken by several manufacturers, including:
| Manufacturer | Quantity |
| Remington Rand | 900,000 |
| Colt | 400,000 |
| Ithaca Gun Company | 400,000 |
| Union Switch & Signal | 50,000 |
| Singer | 500 |
M1911A1 pistols produced during WWII were given a parkerized metal finish instead of bluing, and the wood grip panels were replaced with panels made of brown plastic.
Among collectors today, the Singer-produced pistols in particular are highly prized, commanding high prices even in poor condition.

### M45 MEU(SOC)

In 1986, the USMC Precision Weapon Section (PWS) at Marine Corps Base Quantico began customizing M1911A1s for reconnaissance units. The units served in a new Marine Corps program Marine expeditionary unit (special operations capable) (MEU(SOC)). The pistol was designated the M45 MEU(SOC).
Hand-selected Colt M1911A1 frames were gutted, deburred and were then assembled with after-market grip safeties, ambidextrous thumb safeties, triggers, improved high-visibility sights, accurized barrels, grips, and improved Wilson magazines. These hand-made pistols were tuned to specifications and preferences of end users.
In the late 1980s, the Marines laid out a series of specifications and improvements to make Browning's design ready for 21st-century combat, many of which have been included in MEU(SOC) pistol designs, but design and supply time was limited.
The Los Angeles Police Department was pleased with their special Kimber M1911 pistols, a single source request was issued to Kimber for just such a pistol despite the imminent release of their TLE/RLII models.
Kimber shortly began producing a limited number of what would be later termed the Interim Close Quarters Battle pistol (ICQB).
Maintaining the simple recoil assembly, 5-inch barrel (though using a stainless steel match grade barrel), and internal extractor, the ICQB is not much different from Browning's original design.

### M1911-A2

Due to an increased demand for M1911 pistols among Army Special Operations units, who are known to field a variety of M1911 pistols, the U.S. Army Marksmanship Unit began looking to develop a new generation of M1911s and launched the M1911-A2 project in late 2004.
The goal was to produce a minimum of seven variants with various sights, internal and external extractors, flat and arched mainspring housings, integral and add-on magazine wells, a variety of finishes and other options, with the idea of providing the end-user a selection from which to select the features that best fit their missions.
The AMU performed a well-received demonstration of the first group of pistols to the Marine Corps at Quantico and various Special Operations units at Ft. Bragg and other locations. The project provided a feasibility study with insight into future projects.
Models were loaned to various Special Operations units, the results of which are classified. An RFP was issued for a Joint Combat Pistol but it was ultimately canceled.
Ultimately, the M1911A2 project provided a testbed for improving existing M1911s. An improved M1911 variant becoming available in the future is a possibility.

### M45A1

In July 2012, the USMC awarded Colt a $22.5 million contract for up to 12,000 M45A1 pistols with an initial order of 4036 pistols to replace the M45 MEU(SOC) pistol.
The Marine Corps issued the M45A1 to Force Reconnaissance companies, Marine Corps Special Operations Command (MARSOC) and Special Reaction Teams from the Provost Marshal’s Office.
The new 1911 was designated M45A1 or "Close Quarters Battle Pistol" CQBP. The M45A1 features a dual recoil spring assembly, Picatinny rails and is cerakoted tan in color.
In 2019, the USMC selected the SIG Sauer M18 to replace the M45A1. The Marines began the roll out of the M18 in 2020. The replacement was completed by October 2022.

### Colt-produced models

| Model | Era | Description |
| Colt Commander | 1949 - present | In 1949 Colt began production of the Colt Commander, an aluminum-framed 1911 with a 4+1⁄4 inch barrel and a rounded hammer. It was developed in response to an Army requirement issued in 1949, for a lighter replacement for the M1911 pistol, for issue to officers. |
| Colt Combat Commander | 1970 - present | In 1970, Colt introduced the all-steel "Colt Combat Commander", with an optional model in satin nickel. To differentiate between the two models, the aluminum-framed model was renamed the "Lightweight Commander". |
| Colt Government Mk. IV Series 70 | 1970 - 1983 | Introduced the accurized Split Barrel Bushing (collet bushing). The first 1000 prototypes in the serial number range 35800NM–37025NM were marked BB on the barrel and the slide. Commander-sized pistols retained the solid bushing. |
| Colt Government Mk. IV Series 80 | 1983 -present | Introduced an internal firing pin safety and a new half-cock notch on the sear; pulling the trigger on these models while at half-cock will cause the hammer to drop. Models after 1988 returned to the solid barrel bushing due to concerns about breakages of collet bushings. |
| Colt Gold Cup National Match 1911/Mk. IV Series 70/Mk. IV Series 80 | 1983 - 1996 | MKIV/Series 70 Gold Cup 75th Anniversary National Match/Camp Perry 1978. Limited to 200 pistols. |
| Gold Cup MKIV Series 80 National Match | 1983 - 1996 | Colt-Elliason adjustable rear sight, fully adjustable Bomar-Style rear sight, target post front sight, spur hammer, wide target trigger, lowered and flared ejection port, National Match barrel, beveled top slide, wrap-around rubber stocks with nickel medallion. |
| Colt 1991 Series | 1991 - 2001 ORM; 2001 - present NRM | A hybrid of the M1911A1 military model redesigned to use the slide of the Mk. IV Series 80; these models aimed at providing a more "mil-spec" pistol to be sold at a lower price than Colt's other 1911 models in order to compete with imported pistols from manufacturers such as Springfield Armory and Norinco. The 1991–2001 model used a large "M1991A1" roll mark engraved on the slide. The 2001 model introduced a new "Colt's Government Model" roll mark engraving. The 1991 series incorporates full-sized blued and stainless models in either .45 ACP or .38 Super, as well as blued and stainless Commander models in .45 ACP. |

### Other models

Working for the U.S. Ordnance Office, David Marshall Williams developed a .22 training version of the M1911 using a floating chamber to give the .22 long rifle rimfire recoil similar to the .45 version.
As the Colt Service Ace, this was available both as a pistol and as a conversion kit for .45 M1911 pistols.

### Custom models

Since its inception, the M1911 has lent itself to easy customization. Replacement sights, grips, and other aftermarket accessories are the most commonly offered parts, more so since the 1950s and the rise of competitive pistol shooting.
Price ranges from a low end of around $400 for basic models imported from Turkey (TİSAŞ and GİRSAN) and the Philippines (Armscor, Metro Arms, and SAM Inc.) to more than $4,000 for the best competition or tactical versions (Dan Wesson, Les Baer, Nighthawk Custom, Springfield Custom Shop, and Wilson Combat).
These modifications can range from changing the external finish, checkering the frame, to hand fitting custom hammers, triggers, and sears. Some modifications include installing compensators and the addition of accessories such as tactical lights and even scopes.
A common modification of John Browning's design is to use a full-length guide rod that runs the full length of the recoil spring.
This adds weight to the front of the pistol, but does not increase accuracy, and does make the pistol slightly more difficult to disassemble. As of 2002, custom guns could cost over and are built from scratch or on existing base models.

### International variants

| Model | Origin | Calibre |
| IMBEL M973 | Brazil | 9mm |
| Norinco 1911 | China | .45 ACP |
| Norinco NP-30 | China | .45 ACP |
| Norinco NP-28 | China | 9mm |
| Norinco NP-29 | China | 9mm |
| Kongsberg Colt | Norway | .45 ACP |
| STAR Model B | Spain | 9mm Parabellum |
| ASTRA 1911PL | Spain | 9mm Parabellum |
| Llama Model IX | Spain | 9mm Parabellum |
| Model 1927 Sistema Colt | Argentina | .45 ACP |
| Ballester–Molina | Argentina | .45 ACP |
| Rock Island Armory 1911 series | Philippines | Various |
| T51 pistol | Republic of China | .45 ACP |
| Type 86 | Thailand | .45 ACP |
| MC 1911 | Turkey | .45 ACP |
| Obregón pistol | Mexico | .45 ACP |
| Arsenal Firearms AF2011A1 | Italy | .45 ACP |
| Busanjin Colt | South Korea | .45 ACP |

## Usage

The M1911 design has been offered commercially and has been used by other militaries.
The M1911 was likewise widely copied, and their localised variants remain in use worldwide to date.

### During wartime
#### World War I

By the beginning of 1917, a total of 68,533 M1911 pistols had been delivered to U.S. armed forces by Colt's Patent Firearms Manufacturing Company and the U.S. government's Springfield Armory.
The M1911 and M1911A1 pistols were also ordered from Colt or produced domestically in modified form by several other nations, including Brazil, Mexico, Argentina and Spain.

#### World War II

The M1911A1 was a favored small arm of both U.S. and allied military personnel during the war.
In particular, the pistol was prized by some British commando units and Britain's highly covert Special Operations Executive, as well as South African Commonwealth forces.
Numbers of Colt M1911s were used by the Royal Navy as sidearms during World War I in .455 Webley Automatic caliber.
The pistols were then transferred to the Royal Air Force where they saw use in limited numbers up until the end of World War II as sidearms for aircrew in event of bailing out in enemy territory.
The German Volkssturm also used captured M1911s at the end of World War II under the weapon code P.660(a), in which the letter 'a' refers to "Amerika", the weapon's country of origin.

## Users
### Current

* Brazil
* Bolivia
* Chile
* Colombia
* Costa Rica
* Dominican Republic
* Greece
* East Timor
* Egypt
* Ecuador
* Egypt
* Fiji
* Georgia
* Guatemala
* Haiti
* Indonesia
* Iran
* Liberia
* Lithuania
* Malaysia
* Mexico
* Nicaragua
* North Korea
* Philippines
* Papua New Guinea
* Republic of China
* South Korea
* Thailand
* United States
* Vietnam
* Zimbabwe

### Former

* Argentina: Manufactured M1911 pistols under license from 1945 to 1966 by Dirección General de Fabricaciones Militares.
* Austria
* Belgium
* Canada: In both World Wars, Canadian officers had the option of privately purchasing their own sidearm and the M1911/M1911A1 was a popular choice. The joint Canadian-US First Special Service Force (aka "The Devil's Brigade") also used American infantry weapons, including the M1911A1.
* China: Some use indigenously-made copies.
* Cuba
* El Salvador
* Estonia: replaced by USP pistols
* Ethiopian Empire: used by the Kagnew Battalion
* Finland: About 51,000 bought by Russian military from United States in years 1915–1917. But only relatively small number of these captured pistols ended up to hands of authorities after Finnish Civil War. Finnish military had about 120 pistols during World War 2, most of them were issued to field army.
* France: 5,500 M1911 received during World War I, especially for tank units, officers and trench raiders. Free French Forces received 19,325 Colts. Known in French service as Pistolet automatique 11 mm 4 (C.45) (Automatic pistol 11.4mm (calibre .45)). Both M1911 and M1911A1 pistols were used.
* Democratic Republic of Georgia
* Kingdom of Laos: Received M1911A1s from US during Laotian Civil War (1955-1975).
* Luxembourg: In service with 1st Artillery Battalion 1963–1967.
* Nazi Germany: Used captured pistols during World War II.
* New Zealand: Used during WWII
* Japan: After World War II, the Japan Self-Defense Forces and Police were provided 101,700 M1911A1s from the US. These were used until the 1980s.
* Netherlands: 50 received during World War I
* Norway: 700 received during World War I Produced under license as Kongsberg Colt.
* Panama: Used by the Panama Defense Forces
* Poland: Polish Armed Forces in the West used pistols during World War II.
* Russian Empire: 51,000 purchased between February 1916 and January 1917
* Shanghai International Settlement: Colt M1911 and M1911A1s were used by non-Chinese members of the Shanghai Municipal Police from 1926
* South Vietnam
* Soviet Union: Some M1911 pistols were captured during Allied intervention in the Russian Civil War and used in Red Army. Extra 12,977 pistols were received as Lend-Lease during World War II.
* United Kingdom: Some M1911s chambered for .455 Webley Automatic were supplied to the Royal Flying Corps during WWI. Saw service among elite and special forces during WWII in .45 and .455. Possibly still in use by UKSF.
* United States:
** Vernon Police Department, California
* Viet Cong: Crude clones used by VC guerrillas with some captured in the Vietnam War.

## Legacy

The M1911A1 is popular among the general public in the U.S. for practical and recreational purposes.

### Civilian use

The M1911 is commonly used for concealed carry thanks in part to a single-stack magazine (which makes for a thinner pistol that is, therefore, easier to conceal), personal defense, target shooting, and competition as well as collections.
There are a growing number of manufacturers of M1911-style pistols and the model continues to be quite popular for its reliability, simplicity, and patriotic appeal.
The M1911 is popular with civilian shooters in competitive events such as the International Defensive Pistol Association and International Practical Shooting Confederation, showing no signs of decreasing popularity.

### State firearm

On March 18, 2011, the U.S. state of Utah—as a way of honoring M1911 designer John Browning, who was born and raised in the state—adopted the Browning M1911 as the "official firearm of Utah".

### Military and law enforcement

The M1911 served as the standard-issue sidearm for the United States Armed Forces from 1911 to 1985.
It was widely used in World War I, World War II, the Korean War and the Vietnam War. It also has seen service in the Desert Storm, Operation Iraqi Freedom and Operation Enduring Freedom, albeit to a different extent.
Many military and law enforcement organizations in the U.S. and other countries continue to use (often modified) M1911A1 pistols, notably Los Angeles Police Department SWAT., the FBI Hostage Rescue Team, and Delta Force.

## Similar pistols

* AMT Hardballer
* Ballester–Molina
* Browning Hi-Power
* Kimber Custom
* Kongsberg Colt
* M15 pistol
* Obregón pistol
* FB Vis
* FN Model 1903
* Rock Island Armory 1911
* Ruger SR1911
* SIG Sauer 1911
* Smith & Wesson SW1911
* Springfield Armory 911
* Springfield Armory EMP
* Star Model BM
* TT pistol