M1911 M1911A1 Pistol

The M1911 Colt .45 Automatic Pistol is one of the most successful designs in the history of firearms. The M1911 and M1911A1 pistols served as the primary U.S. military sidearm for about 80 years through two World Wars, Korea, Vietnam and countless other engagements.

Automatic Pistol, Caliber .45, M1911A1
Automatic Pistol, Caliber .45, M1911A1.

More photos and videos of the M1911 Colt .45 Automatic Pistol are available at the linked page.

Today in WW II: 23 Sep 1940 After just seven weeks of development, American Bantam delivers the first prototype jeep to Camp Holabird, MD.   

History of the M1911 Colt Automatic Pistol

The commercial .45 automatic pistol was designed by John Moses Browning. It was first mass-produced by Colt, as its M1905, then adopted, in modified form, by the U.S. Army in 1911 as the Automatic Pistol, Caliber .45, Model of 1911", chambered for the .45 cal. ACP cartridge. It won fame in WWI and was re-designated as the "Pistol, U.S. Caliber .45 Model 1911A1" in 1922 when some minor design improvements were introduced. About 150,000 were produced before World War II. Colt, Remington-Rand, Union Switch & Signal and the Ithaca Gun Company manufactured 1,800,000 pistols during WWII. Production ended in 1945 but the substantial inventories were in service for decades afterward until replaced by the M9 Beretta 9mm automatic pistol.

Automatic Pistol, Caliber .45, M1911A1
Automatic Pistol, Caliber .45, M-1911A1.

The classic .45 cal. Colt automatic pistol was much sought after by GIs as a personal back-up weapon. It was officially issued to officers, NCOs, demolition personnel and vehicle crews. Many other soldiers and officers obtained and carried a "45" without authorization.

The M-1 belt holster and the M-3 shoulder holster were issued for the pistol. Most Airborne soldiers carried their pistols in M-3 shoulder holsters.

Characteristics of the M1911A1 Colt Automatic Pistol

Automatic Pistol, Caliber .45, M1911A1 Magazine Clip

The .45 caliber semiautomatic pistol M1911A1 (a.k.a. the "Colt .45") is a conventional semi-automatic pistol, holding seven rounds in a detachable magazine (photo, left). It is 8 inches long and weights 2 pounds. It has a muzzle velocity of 860 fps and uses a .45 caliber ACP (Automatic Colt Pistol) cartridge. It has considerable "stopping power" in close-in fighting. Most have a lanyard loop attached to the pistol grip's base for attaching either the 1918 or 1943 lanyards.

The .45 caliber semiautomatic pistol M1911A1 is a recoil-operated hand weapon. The magazine-fed semiautomatic weapon fires one round each time the trigger is squeezed once the hammer is cocked by prior action of the slide or thumb. This design is referred to as "single action only." The thumb safety may only be activated once the pistol is cocked. The hammer remains in the fully cocked position once the safety is activated. (Note: More modern pistol designs of the "double action" type will allow the hammer to move forward to an uncocked position when the thumb safety is activated.)

The M1911A1 was widely respected for its reliability and lethality. However, its single action, cocked and locked design required the user to be very familiar and well-trained to allow carrying the pistol in the "ready-to-fire" mode. Consequently, M1911A1s were often prescribed to be carried without a round in the chamber. Even with this restriction on the user, numerous unintentional discharges were documented yearly.

Differences Between the M1911 and M1911A1 Colt Automatic Pistols

The M1911 and M1911A1 models of the .45 Automatic pistol are quite similar, with the changes in the following list the only differences:

  • Tang on the grip safety was lengthened to protect the shooter's hand from the hammer
  • Receiver is cut back on the right side behind the trigger to allow a more natural position for the shooter's trigger finger
  • Trigger face is cut back and ridged for better finger pressure control
  • Mainspring housing at the bottom, rear of the handle is arched and knurled to improve shooter's grip
  • Front sight top is wider to facilitate aiming

For immediate identification, the curved shape of the back of the mainspring housing indicates that the pistol is an M1911A1 as opposed to the straight housing on the M1911. Most military production of the Colt .45 Automatic pistols was of the Model M1911A1.

Replacement of the M1911A1 by the Beretta 92F

On 14 January 1985 the Pentagon announced that the Model 92F 9mm pistol manufactured by Fabbrica D' Armi Pietro Beretta S.p.A. of Italy would officially replace the M1911A1 .45 caliber pistol. The new pistol would be known as "Pistol, Automatic, Caliber 9mm, M9" to be manufactured by a Beretta subsidiary in the U.S. Actual replacement of the M1911A1 by the M9 took place from the late 1980s into the 1990s while production problems with the M9 Beretta were worked out.

In August 2005, the DoD issued specifications for the Military Forces Joint Combat Pistol (JCP), a possible replacement for the M9 Pistol. The specification requires the JCP to be chambered for .45 ACP ammunition. The JCP procurement was postponed in 2006, but it seemed clear that the days of the M9 9mm pistol were coming to an end and that its successor may return to the reliable .45 ACP cartridge.

MEU (SOC) and M45 Close Quarter Battle Pistol

Automatic Pistol, Caliber .45, M1911A1 USMC Modification in 1986: MEU (SOC)

The M1911A1 had been the standard handgun issued to Marines for many decades. Selected weapons were modified in the 1980s to meet the requirements of the Marine Expeditionary Unit (Special Operations capable) or MEU (SOC) in lieu of arming them with the M9 9mm pistol. 500 pistols were selected and modified.

Weapon modifications were designed in 1986 to meet the requirements of the MEU (SOC). Each pistol is hand-built by specially trained armorers at the Rifle Team Equipment (RTE) shop, Quantico, Virginia. The weapon is a modified M1911A1 .45 caliber pistol sometimes referred to as "near match" or "combat accuratized." The MEU (SOC) Pistol is the designated backup weapon of Marines armed with the 9mm MP5-N Close Quarters Battle weapon. The M1911A1 was chosen for this role (and its modifications generated) because of its inherent reliability and lethality, and because the MEU(SOC) modifications make the M1911A1 design more "user friendly."

The unique characteristics of the MEU (SOC) pistol are:

  • Commercial/competition grade ambidextrous safety
  • Precision barrel
  • Precise trigger
  • Rubber coated grips
  • Rounded hammer spur
  • High profile combat sights
In addition, an extra-wide grip safety provides for increased comfort and controllability (which aids in a quick follow-up second shot). The issue magazines are replaced with stainless steel competition-grade magazines with rounded plastic follower and extended floor plate.

In 2005, the Corps bought 150 MEU (SOC) pistols from Springfield Armory in Geneseo, IL. In October 2010, the USMC sought a vendor for up to 12,000 of the MEU(SOC) .45 cal. pistols, now designated the M45 Close Quarter Battle Pistol, for issue to Marine Forces Special Operations Command and Force Recon. The USMC FY2013 budget submitted in February 2012 included $3 million for the M45 CQBP, citing a doubling of requirements due to the formation of MARSOC and the reconstitution of the Force Reconnaissance Company in each MEF.

Recommended Books about the M1911/M1911A1 Pistol

Production and Serial Numbers: U.S. Pistol M1911 & M1911A1 .45

The figures in this table were compiled by Springfield Armory and are the best numbers available on the web. However, careful research may reveal gaps and problems.

Year S/N Range and Manufacturer(s) Total Produced
1912 1-17250 Colt 17250
1913 17251-60400 Colt 43150
1914 60401-72750 Colt
83856-102596 Colt
72751-83855 Springfield
102597-107596 Springfield
1915 107597-113496 Colt
120567-125566 Colt
113497-120566 Springfield
125567-133186 Springfield
1916 133187-137400 Colt 4214
1917 137401-210386 Colt
210387-215386 Colt (frames only)
215387-216986 Colt
1918 216987-594000 Colt
1-13152 Remington UMC
1919 594001-629500 Colt
13153-21676 Remington UMC
629,501-700000 (unknown)
1924 700001-710000 Colt 10000
1937 710001-712349 Colt 2349
1938 712350-713645 Colt 1296
1939 713646-717281 Colt 3636
1940 717282-721977 Colt 4696
1941 721978-756733 Colt 34756
1942 756734-800000 Colt
800501-856100 Colt
S800001-S800500 Singer
800501-856100 Defaced, renum. by RIA
865305-856404 Defaced, renum. by R.I.A.
856101-856304 Defaced, renum. by Augusta Arsenal
1943 856405-916404 Ithaca
1208674-1279673 Ithaca
1441131-1471430 Ithaca
916405-1041404 Remington Rand
1279699-1441430 Remington Rand
1471431-1609528 Remington Rand
1041405-1096404 US&S Co.
1096405-1208673 Colt
1279674-1279698 Renumbered Augusta Arsenal
1944 1609529-1743846 Colt
1816642-1890503 Ithaca
1471431-1609528 Remington Rand
1743847-1816641 Remington Rand
1890504-2075103 Remington Rand
1945 2075104-2134403 Ithaca
2619014-2693613 Ithaca
2134404-2244803 Remington Rand
2380014-2619013 Remington Rand
2244804-2380013 Colt

X2693614-X2693665 Renumbered Raritan Arsenal X2693666-X2693785 Renumbered RIA X2693786-X2693885 Renumbered Ord. in Tokyo Arsenal X2693886-X2694996 Renumbered several U.S. Arsenals X2694997-X2694998 Renumbered RIA 1954-1955 X2694999-X2695198 Renumbered Ord. in Tokyo Arsenal 1955 X2695199-X2695201 Renumbered Raritan Arsenal 1955 X2695202-X2695210 Renumbered RIA 1955-1956 X2695211-X2695212 Renumbered Minn. Mil. Dist. Arsenal 1957 Total: 4985 Total all sources 1912-1965 - 2,769,094

RUSSIAN CONTRACT 1915-1916-C50000-C84000 (These pistols were selected at random from the above serial numbers and marked ANGLO ZAKAZIVAT.)


BRITISH CONTRACT .445 CALIBER 1915-1916-W83001-W111000 (The majority of these guns were issued to the Royal Navy. In 1942, they were reissued to the Royal Air Force. At this time they were handstamped on the frame R.A.F. or RAF.

Colt M1911A1 pistols with serial numbers beginning with WK or WMK are commemorative reproductions, not original military production.


REMINGTON U.M.C. Major E.E. Chapman, Inspector Lt. Arthur E. Evans, Sub-inspector Lt. Paul M. Buzby, Sub-inspector

COLT F.B. Austin Lt. R.W. Chandler T.L. Childs E.H. Dewey Col. Guy H. Drewry Andrew H. Forsythe F.L. Hosmer Lt. Charles G. Howe A.L. Hallstrom Cpt. Walter T. Gorton K.S. Morse Maj. W.G. Penfield Charles F. Rogers W.E. Strong D.A. Turner Col. Robert Sears

REMINGTON RAND Col. Frank J. Atwood LTC Harrison Shaler

ITHACA Col. Frank J. Atwood

UNION SWITCH & SIGNAL Col. Frank J. Atwood LTC R.C. Downie

SINGER LTC John K. Christmas


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