.45 Caliber Powerhouse: The Story of the Iconic M1911A1 Gun

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Key Points and Summary: The Colt M1911A1 pistol, designed by John Browning, served the US military for over a century, a testament to its exceptional design and combat effectiveness.

-Born from the need for greater stopping power during the Philippine Insurrection, the .45 caliber M1911 proved incredibly reliable, outperforming competitors in rigorous testing.

-It saw action in both World Wars, Korea, and Vietnam, earning a reputation for ruggedness and lethality.

-Despite being replaced by the 9mm Beretta M9 in the 1980s, the M1911A1 remained in service with some Special Operations units. Its legacy as a legendary combat firearm endures.

Combat Excellence: Why the M1911A1 Served the U.S.Military So Long 

The Colt M1911A1 served the US military faithfully from 1911 to 2023, lasting 113 years of combat excellence. In today’s world of precise manufacturing and engineering, that is a ridiculously long service life for a combat pistol. 

That speaks to the outstanding design of John Moses Browning. Browning designed some of the most successful firearms of all time. During a roughly fifty-year period, Browning designed the M1911A1 pistol, the Browning Hi-Power pistol, the Browning Automatic Rifle (BAR), the M1917 and M1919 .30-caliber machine guns, and the ubiquitous M2 .50 caliber heavy machine gun. The M2 is still a mainstay in the US military and several others.

The M1911A1 is the most successful combat pistol in history. 

History of the M1911 Pistol

The M1911 Colt Automatic Pistol was born out of revolution. The Philippine Insurrection, also known as the Moro Rebellion, took place between 1899 and 1902, during the same time period as the Spanish-American War. The US fought the Moro tribespeople in the Philippine Islands.

The Moro were a Muslim tribe who used a combination of their religious beliefs and narcotics to work themselves up in a frenzy and show fearlessness in combat. The Moro were almost berserker-like in close-quarters combat, and the older .38 caliber revolvers carried by soldiers and Marines did little to stop or even slow down the charging Moro. Soldiers needed a more effective pistol round.

The Army wanted a new design that was no less than .45 caliber. Several arms manufacturers submitted designs in 1910 to test: Bregman, Colt, DVM, Knoble, Savage, Wembley, and White-Merrill. The Colt’s reliability won the day due to its reliability. One Colt Pistol fired 6,000 rounds without a misfire during a stress test. When the weapon would get too hot, the testers would plunge the pistol into a bucket of cold water. The nearest competitor suffered 37 malfunctions.

The  1911 Colt used for tests, designed by Browning, was a magazine-fed, single-action semi-automatic pistol with both manual and grip safeties. The pistol was rugged, had outstanding stopping power, was very easy to field strip, and was dependable. The US Army adopted the Colt in 1911 and dubbed it the M1911. The Marine Corps soon followed suit. And a legend was born. 

World War I, WWII, Korea, and Vietnam

The M1911 was adopted in the military in the nick of time before the US entered World War I. The pistol was renowned for its stopping power and reliability. During one particular battle, on October 8, 1918, CPL Alvin C. York of the 328th Infantry Regint, 82nd Infantry Division, was awarded the Medal of Honor. 

York and his squad were caught behind enemy lines and pinned down by murderous machine gun fire. York crawled forward to eliminate the machine gun nest. York began picking off the machine gunners and then was charged by six men with bayonets. York, known for his accuracy, placed six well-aimed shots with his M1911 and killed all six attackers. His attack captured 36 machine guns and 132 officers and men. 

During the post-war years, Colt made a few minor modifications, including scalloping the trigger housing, a longer safety spur, and wider sights, which resulted in the Colt M1911A1. The US produced 1.9 million 1911A1 pistols during WWII. Many in the British Commandos, SAS, South African Commandos, and others preferred the M1911A1 because of its stopping power.

During the Korean War, Brigadier General S.L.A. Marshall, in his outstanding “Commentary on Infantry Operations and Weapons Usage in Korea, Winter of 1950-1951,” found, “The pistol is of definite value in the type of warfare experienced by Eighth Army, and one hears more words said about its proved usefulness than during either World War.”

The M1911A1 continued to serve well in the war in Vietnam. 

The US Military Replaces the M1011A1

But during the late-1970s, the Army began looking for a replacement. Logistics in a potential shooting war with the Soviets was planned for, and the US, wanting to ease the strain, favored adopting the 9mm Parabellum (Luger) cartridge. 

After several trials, the Beretta 92F was selected and dubbed the M9. I’ve written on the decision to replace the .45 with the M9, so no further discussion is needed.

However, many units in the Special Operations Command (SOCOM) continued to use the .45, and many troops in Special Forces units tinkered with the pistols to keep them going. 

The M9 served for a few decades until the Army replaced it with the M17 and M18 made by Sig Sauer.

The Marine Corps kept a modified M1911A1, the M45A1 Close Quarters Battle Pistol, in its inventory until 2023. Colt, which has produced pistols for the US Army since 1846, does not have a pistol in the military’s inventory.

The legend of the M1911A1, however, will live on. 

About the Author

Steve Balestrieri is a 19FortyFive National Security Columnist. He served as a US Army Special Forces NCO and Warrant Officer. In addition to writing for 19FortyFive, he covers the NFL for PatsFans.com and is a member of the Pro Football Writers of America (PFWA). His work was regularly featured in other military publications.