The .45 caliber semiautomatic pistol M1911A1 is a recoil-operated hand weapon. It is a magazine-fed semiautomatic weapon, which 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.
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 MEU(SOC) in lieu of arming them with the M9 9mm pistol. #45 #45_caliber_handgun #45_claiber #caliber #hunting #semiautomatic