M9 Pistol
Overview
The Beretta M9, formally Pistol, Semiautomatic, 9mm, M9, is a 9×19mm Parabellum pistol of the United States military
Military of the United States
The United States Armed Forces are the military forces of the United States. They consist of the Army, Navy, Marine Corps, Air Force, and Coast Guard.The United States has a strong tradition of civilian control of the military...

 adopted in 1985. It is essentially a military specification Beretta 92F
Beretta 92
The Beretta 92 is a series of semi-automatic pistols designed and manufactured by Beretta of Italy. The model 92 was designed in 1972 and production of many variants in different calibers continues today...

, later the 92FS.

The M9 won a competition in the 1980s to replace the M1911A1
M1911
The M1911 is a single-action, semi-automatic, magazine-fed, and recoil-operated handgun chambered for the .45 ACP cartridge. John M. Browning designed the firearm which was the standard-issue side arm for the United States armed forces from 1911 to 1985. The M1911 is still carried by some U.S....

 as the primary handgun of the U.S. military, beating out many other contenders, and only narrowly defeating the SIG P226
SIG P226
The SIG P226 is a full-sized, service-type pistol made by SIG Sauer. It is chambered for the 9×19mm Parabellum, .40 S&W, .357 SIG, and .22 Long Rifle. It is essentially the same basic design of the SIG P220, but developed to use higher capacity, staggered-column magazines in place of the...

 for cost reasons.
 
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