The Italian company Beretta created and produced the Beretta 92, Beretta 96, and Beretta 98 series of semi-automatic pistols. In 1975, the Beretta 92 was created, and in 1976 it was put into production. Even now, a wide variety of calibers and modifications are still in use. The Beretta 92FS, also known as the "M9", took the place of the.45 ACP M1911A1 pistol in the US military in 1985. The M1923 and M1951 are two of the most notable older Beretta designs from which the Beretta 92 pistol emerged. The open slide design originates from the M1923 while the alloy frame and locking block barrel, which were originated from the Walther P38, were utilized for the first time in the M1951. Other characteristics of older Beretta pistols included the grip angle and the front sight that was integrated with the slide. The 1974 .380 caliber Model 84 was the first firearm to use what were perhaps the two most significant advanced design aspects of the Model 92. There was no feed ramp between the magazine and the chamber due to direct feed, which was a feature of both of these advancements (a Beretta innovation in pistols). Additionally, the magazine had a "double-stacked" design, a feature that was first used on the Browning Hi-Power in 1935. The final design was developed in 1975 with help from skilled firearms designers Carlo Beretta, Giuseppe Mazzetti, and Vittorio Valle. Production lasted from May 1976 until February 1983.