Colt 1911

The **M1911** is a single-action, semi-automatic, magazine-fed, recoil-operated pistol chambered for the .45 ACP cartridge.[1] It served as the standard-issue sidearm for the United States Armed Forces from 1911 to 1986. 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 pistol's 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.[1]

In total, the U.S. 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 October 1986, 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.[4]

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 relatively slim width and the power of the .45 ACP cartridge.[5]

## 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 then in service.[6] The United States was adopting new firearms at a phenomenal rate; several new pistols and two all-new service rifles (the 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 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 bullet 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.[7]

M1911 designer, John Browning

During the end of 1899 and start of 1900, a test of self-loading pistols was conducted, which included entries from Mauser (the C96 "Broomhandle"), Mannlicher (the Mannlicher M1894), and Colt (the Colt M1900).[6]

This led to a purchase of 1,000 DWM Luger pistols, chambered in 7.65mm Luger, a bottlenecked cartridge. 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
 (known in current military parlance as the 9×19mm NATO), a necked-up
version of the 7.65 mm round. Fifty of these were tested as well by the U.S. Army in 1903.[8]

American units fighting Moro guerrillas 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 very high battle morale and frequently used drugs to inhibit the sensation of pain.[9] 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.[10] The problems prompted the then–Chief of Ordnance, General William Crozier, to authorize further testing for a new service pistol.[10]

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.[10] This led to the 1906 trials of pistols from six firearms manufacturing companies (namely, Colt, Bergmann, Deutsche Waffen und Munitionsfabriken (DWM), Savage Arms Company, Knoble, Webley, and White-Merril).[10]

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.[10]
 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,[11]
 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.[10] Both designs were improved between each testing over their initial entries, leading up to the final test before adoption.[10]

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.[10]

### Service history

Comparison of government-issue M1911 and M1911A1 pistols

M15 General Officers adopted by the U.S. Army in the 1970s for issue to Generals.

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 to Model 1911, in 1917, and then M1911, in the mid 1920s.
The Director of Civilian Marksmanship began manufacture of M1911 pistols for members of the National Rifle Association
 in August 1912. Approximately 100 pistols stamped "N.R.A." below the
serial number were manufactured at Springfield Armory and by Colt.[12] The M1911 was formally adopted by the Navy and Marine Corps in 1913.

#### 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 Firearms Company and the U.S.
government's Springfield Armory. However, 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, North American Arms Co. of
Quebec.[13]
 Several other manufacturers were awarded contracts to produce the
M1911, including the National Cash Register Company, the Savage Arms
Company, the Caron Bros. of Montreal, the Burroughs Adding Machine Co.,
Winchester Repeating Arms Company, and the Lanston Monotype Company, but
 the signing of the Armistice resulted in the cancellation of the
contracts before any pistols had been produced.

#### Interwar changes

Battlefield experience in the First World War led to some more small
external changes, 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.[14]
 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).[10]
 These changes were subtle, and largely intended to make the pistol
easier to shoot for those with smaller hands. Many persons unfamiliar
with the design are often unable to tell the difference between the two
versions at a glance. No significant internal changes were made, and
parts remained interchangeable between the M1911 and the M1911A1.[10]

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.[10] As the Colt Service Ace, this was available both as a pistol and as a conversion kit for .45 M1911 pistols.[10]

Colt 1911 01

Before World War II, a small number of modified M1911-pattern pistols
 in .45 caliber were produced under license at the Norwegian weapon
factory *Kongsberg Vaapenfabrikk*, designated "Pistol M/1914" and unofficially known as "Kongsberg Colt".
 Production continued after the German occupation of Norway in 1940. The
 Pistol M/1914 is noted for its unusual extended slide stop which was
specified by Norwegian ordnance authorities. Throughout the M/1914's use
 in Norwegian military service, Norway continued to build the M/1914
pistol as originally specified. These pistols are highly regarded by
modern collectors, with the 920 examples stamped with German Army inspectors proof (Waffenamt) codes and the unknown number of unmarked examples assembled by the Norwegian resistance movement
 (the "Matpakke-Colt" or "Lunch Box Colt") being the most sought after.
German forces also used captured M1911A1 pistols, using the designation
"Pistole 660(a)".[15]

The M1911 and M1911A1 pistols were also ordered from Colt or produced
 domestically in modified form by several other nations, including
Argentina (Modello 1916 and Modello 1927 contract pistols, and the Ballester–Molina), in Brazil by the M1937 contract pistol, in Mexico by M1911 Mexican contract pistols and the Obregón, and in Spain by private manufacturers Star and Llama.

#### World War II

Diagram from the Soldier's Handbook (1940–41), showing the various components of the pistol.

World War II
 and the years leading up to it created a great demand. 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 Remington Rand (900,000 produced), Colt (400,000), Ithaca Gun Company (400,000), Union Switch & Signal (50,000), and Singer
 (500). New M1911A1 pistols were given a parkerized metal finish instead
 of blueing, and the wood grip panels were replaced with panels made of
brown plastic. The M1911A1 was a favored small arm of both US and allied
 military personnel during the war, in particular, the pistol was prized
 by some British commando units and the SOE as well as Commonwealth South African forces.[16][17][18]

So many 1911A1 pistols were produced during the war that the
government cancelled all postwar contracts for new production, instead
choosing to rebuild existing pistols with new parts, which were then
refinished and tested for functioning. From the mid 1920s to the mid
1950s thousands of 1911s and 1911A1s were refurbished at U.S. Arsenals
and Service depots. These arsenal rebuilds consisted of anything from
minor inspections to major overhauls of pistols returned from service
use. Pistols that were refurbished at Government arsenals will usually
be marked on the frame/receiver with the arsenal's initials, such as RIA
 (Rock Island Armory) or SA (Springfield Armory).

Among collectors today, the Singer-produced pistols in particular are
 highly prized, commanding high prices even in poor condition.[19]

#### General Officer's Model

From 1943 to 1945 a fine-grade russet-leather M1916 pistol belt set
was issued to some generals in the US Army. It was composed of a leather
 belt, leather enclosed flap-holster with braided leather tie-down leg
strap, leather two-pocket magazine pouch, and a rope neck lanyard. The
metal buckle and fittings were in gilded brass. The buckle had the seal
of the United States on the center (or "male") piece and a laurel wreath
 on the circular (or "female") piece. The pistol was a standard-issue
M1911A1 that came with a cleaning kit and three magazines.

From 1972 to 1981 a modified M1911A1 called the RIA M15 General Officer's Model
 was issued to General Officers in the US Army and US Air Force. From
1982 to 1986 the regular M1911A1 was issued. Both came with a black
leather belt, open holster with retaining strap, and a two-pocket
magazine pouch. The metal buckle and fittings were similar to the M1916
General Officer's Model except it came in gold metal for the Army and in
 silver metal for the Air Force. The M15 and M1911A1 were replaced with
the M9 pistol in 1986.

#### Replacement for most uses

After World War II, the M1911 continued to be a mainstay of the United States Armed Forces in the Korean War and the Vietnam War. It was used during Desert Storm in specialized U.S. Army units and U.S. Navy Mobile Construction Battalions (Seabees), and has seen service in both Operation Iraqi Freedom and Operation Enduring Freedom, with U.S. Army Special Forces Groups and Marine Corps Force Reconnaissance Companies.[20]

However, 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 9 mm 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. By the later 1980s production was ramping up
despite a controversial XM9 retrial and a separate XM10 reconfirmation
that was boycotted by some entrants of the original trials, cracks in
the frames of some pre-M9 Beretta-produced pistols, and despite a
problem with slide separation using higher-than-specified-pressure
rounds that resulted in injuries to some U.S. Navy special operations
operatives. This last issue resulted in an updated model that includes
additional protection for the user, the 92FS, and updates to the
ammunition used.[21]

By the early 1990s, most M1911A1s had been replaced by the Beretta M9, though a limited number remain in use by special units. The U.S. Marine Corps
 (USMC) in particular were noted for continuing the use of M1911 pistols
 for selected personnel in MEU(SOC) and reconnaissance units (though the
 USMC also purchased over 50,000 M9 pistols). For its part, the United States Special Operations Command (USSOCOM) issued a requirement for a .45 ACP pistol in the Offensive Handgun Weapon System (OHWS) trials. This resulted in the Heckler & Koch OHWS becoming the MK23 Mod 0 Offensive Handgun Weapon System (itself being heavily based on the 1911's basic field strip), beating the Colt OHWS,
 a much modified M1911. Dissatisfaction with the stopping power of the
9 mm Parabellum cartridge used in the Beretta M9 has actually promoted
re-adoption of pistols based on the .45 ACP
 cartridge such as the M1911 design, along with other pistols, among
USSOCOM units in recent years, though the M9 remains predominant both
within SOCOM and in the U.S. military in general.[20]

### Current users in the U.S.

Many military and law enforcement organizations in the United States
and other countries continue to use (often modified) M1911A1 pistols
including Marine Corps Special Operations Command, Los Angeles Police Department SWAT and S.I.S., the FBI Hostage Rescue Team, FBI regional SWAT teams, and 1st Special Forces Operational Detachment—Delta (Delta Force).

A basic version of Smith & Wesson's SW1911 with user-installed Pachmayr grips.

M1911 by Springfield Armory, Inc. (contemporary remake of the World War II G.I. Model, parkerized).

The M1911A1 is popular among the general public in the United States
for practical and recreational purposes. The pistol 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. Numerous aftermarket accessories allow users
to customize the pistol to their liking. There are a growing number of
manufacturers of M1911-type pistols and the model continues to be quite
popular for its reliability, simplicity, and patriotic appeal. Various
tactical, target, and compact models are available. Price ranges from a
low end of around $400 for basic pistols imported from the Philippines
or Turkey (Armscor, Tisas, Rock Island Armory, Girsan, STI Spartan, Seraphim Armoury) to more than $4,000 for the best competition or tactical versions (Wilson Combat, Ed Brown, Les Baer, Nighthawk Custom, and STI International).[22]

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.[2]
 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.[2]
 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.[2] The project provided a feasibility study with insight into future projects.[2]
 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.[2]
 Currently units are experimenting with an M1911 platform in .40 which
will incorporate lessons learned from the A2 project. Ultimately, the
M1911A2 project provided a test bed for improving existing M1911s. An
improved M1911 variant becoming available in the future is a
possibility.[2]

The Springfield Custom Professional Model 1911A1 pistol is produced
under contract by Springfield Armory for the FBI regional SWAT teams and
 the Hostage Rescue Team.[23]
 This pistol is made in batches on a regular basis by the Springfield
Custom Shop, and a few examples from most runs are made available for
sale to the general public at a selling price of approximately US$2,700
each.

#### MEU(SOC) pistol

Main article: MEU(SOC) pistol

Marine Expeditionary Units formerly issued M1911s to Force Recon units.[24]
 Hand-selected Colt M1911A1 frames were gutted, deburred, and prepared
for additional use by the USMC Precision Weapon Section (PWS) at Marine Corps Base Quantico.[24]
 They were then assembled with after-market grip safeties, ambidextrous
thumb safeties, triggers, improved high-visibility sights, accurized
barrels, grips, and improved Wilson magazines.[25] These hand-made pistols were tuned to specifications and preferences of end users.[26]
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.[26]
 Discovering that 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.[27]
 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.[27]

In late July 2012, the U.S. Marines placed a $22.5 million order for 12,000 M1911 pistols for MEU(SOC) forces.[4]
 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.

### Other users over the world

Colt 1911 British Service Model, cal .455 Webley Auto

Numbers of Colt M1911s were used by the UK Royal Navy as sidearms during World War I in .455 Webley Automatic caliber.[10] The pistols were then transferred to the UK Royal Air Force
 where they saw use in limited numbers up until the end of World War II
as sidearms for air crew in event of bailing out in enemy territory.[10] Some units of the South Korean Air Force still use these original batches as officers' sidearms.

Norway used the Kongsberg Colt
 which was a license produced variant and is recognized by the unique
slide catch. Many Spanish firearms manufacturers produced pistols
derived from the 1911, such as the STAR Model B, the ASTRA 1911PL, and the Llama Model IX, just to name a few.[28] Argentina produced a licensed copy, the Model 1927 *Sistema* Colt, which eventually led to production of the cheaper Ballester–Molina, which resembles the 1911, but is not actually based on it.

The German *Volkssturm*
 used captured M1911s at the end of World War II under the weapon code
P.660(a), in which the alphabet means "Amerika", the weapons' origin
country.[29][30]

The Brazilian company IMBEL (*Indústria de Material Bélico do Brasil*) still produces the pistol in several variants for military and law enforcement uses in .45 ACP, .40 S&W
 and 9 mm calibres. The two former are also available to Army-registered
 collectors and shooters. For the civilian market the pistols are
chambered in .380 ACP since there are strong calibre restrictions in place.

The Greek Hellenic Army
 issues the World War II production American M1911 as sidearm. These
pistols are supplied as military aid in 1946 and afterward as the U.S.
aided Greece against Communist expansion.[31]

The Turkish Land Forces uses "MC 1911" Girsan made copy of M1911.[32]

The Royal Thai Army and Royal Thai Police uses the Type 86, the Thai copy of the M1911 chambered in the .45 ACP round,[33] and still uses USGI M1911s supplied as military aid during the Vietnam War era while Rapid Action Battalion (RAB Forces), an anti-terrorist police tactical team in Bangladesh uses this weapon.[34]

The Armed Forces of the Philippines
 issues Mil-spec M1911A1 pistols as a sidearm to the special forces,
military police and officers. These pistols are mostly produced by Colt, though some of them are produced locally by Armscor, a Philippine company specialized in making 1911-style pistols. The Indonesian Army issued a locally produced version of the Springfield M1911, chambered in .45 ACP along with the Pindad P1, the locally manufactured Browning Hi-Power pistol as the standard issue sidearm.

The Canadian company Seraphim Armoury
 brands Filipino manufactured pistols in several models for domestic and
 export use. Pistols are available in .45 ACP and 9 mm calibres for
civilian, military and law enforcement use.

A Chinese Arms manufacturer, Norinco,
 exports a clone of the M1911A1 for civilian purchase as the M1911A1 and
 the high-capacity NP-30, as well 9mm variants the NP-28 and NP-29.
Norinco also manufactured conversion kits to chamber the 7.62×25mm Tokarev round after the Korean War.[33]

As of 2013, the pistol is made under license instead of copying with
Colt manufacturing machinery, due to an agreement between Norinco and
Colt in order to stop Norinco from producing the Norinco CQ rifle. Importation into the United States was blocked by trade rules in 1993 but Norinco still manage to import the weapon into Canada
 and successfully adopted by IPSC shooters, gunsmiths and firearms
enthusiasts there because of the cheaper price of the pistol than the
other M1911s.

In the 1950s, the Republic of China Army used original M1911A1s, and the batches are now still used by some forces. In 1962, Taiwan copied the M1911A1 as the *T51* pistol, and it saw limited use in the Army. After that, the T51 was improved and introduced for export as the *T51K1*. Now the pistols in service are replaced by locally-made Beretta 92 pistols- the T75 pistol.

### Civilian models

A Colt M1991A1 Compact ORM pistol

A Colt M1991A1 Compact ORM pistol with slide locked back to expose bull barrel.

* **Colt Government Mk. IV Series 70** (1970–1983): Introduced the

accurized Split Barrel 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.

* **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
Model 80; these models aimed at providing a more "mil-spec" pistol to be
 sold at a lower price point 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 "M1991-A1" rollmark
 engraved on the slide. The 2001 model introduced a new "Colts
Government Model" rollmark 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.

### Custom models

A Colt Series 80 Gold Cup National Match edition with nickel plating

Tenring Custom Colt

Since its inception, the M1911 has lent itself to easy customization.
 Replacement sights, grips, and other aftermarket accessories are the
most commonly offered parts. Since the 1950s and the rise of competitive
 pistol shooting, many companies have been offering the M1911 as a base
model for major customization. These modifications can range from
changing the external finish, checkering the frame, and hand fitting
custom hammers, triggers, and sears. Some modifications include
installing compensators and the addition of accessories such as tactical lights and even scopes.[35]
 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.[36] Custom guns can cost over $5000 and are built from the ground up or on existing base models.[37] The main companies offering custom M1911s are: Springfield Custom Shop, Ed Brown, STI International, Nighthawk Custom, Wilson Combat, and Les Baer.[*citation needed*] ISPC models are offered by both Strayer Voigt Inc (Infinity Firearms) and STI International.

## Design

Springfield Mil Spec partially field stripped

Browning's basic M1911 design has seen very little change throughout its production life.[1] The basic principle of the pistol is recoil operation.[1]
 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.[1]

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's vertical impact
surface. 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 it out and away from the pistol. The slide stops and
is then propelled forward by a 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.[1]

The military mandated a grip safety and a manual safety.[1] 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.[1] 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.[38][39]
 Language cautioning against placing the index finger along the side of
the gun to assist in aiming was included in the initial M1911 manual,
and later manuals up to the 1940s.[40]

The same basic design has been offered commercially and has been used
 by other militaries. In addition to the .45 ACP (Automatic Colt
Pistol), models chambered for .38 Super, 9×19mm Parabellum, 7.65mm Parabellum, 9mm Steyr,[41] .400 Corbon, and other cartridges were offered. The M1911 was developed from earlier Colt designs firing rounds such as .38 ACP.
 The design beat out many other contenders during the government's
selection period, during the late 1890s and early 1900s, up to the
pistol's adoption. 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.[42]

Despite being challenged by newer and lighter weight pistol designs in .45 caliber, such as the Glock 21, the SIG Sauer P220, the Springfield XD and the Heckler & Koch USP,
 the M1911 shows no signs of decreasing popularity and continues to be
widely present in various competitive matches such as those of USPSA, IDPA, IPSC, and Bullseye.[2]