The SIG P220 is a semi-automatic pistol designed in Switzerland by Swiss Arms AG (formerly SIG Arms AG, distributed in United States by SIG Sauer). It is manufactured in Eckernforde, Germany, by J.P. Sauer und Sohn GmbH.The SIG P220 also comes in P220R and P220ST versions. The base and R models have an aluminium alloy frame with a stainless steel slide (if made by SIG Sauer in the US; German made versions still use stamped blued steel slide); the ST model has a stainless steel frame and slide. The R and ST models also have a Picatinny rail, beneath the slide and barrel, allowing for fitting of accessories such as tactical lights or laser aiming aids. The P220 was initially imported to the United States as the Browning Double Action (BDA) and then as the P220. It was offered for sale in 9 mm, .38 Super (a rare model), and .45 ACP. However, all modern P220 variants are only available in .45 ACP.The SIG P220 was developed for the Swiss Army as a replacement for the SIG P210, which had been developed during World War II; in service it is known as "Pistole 75" (P75). For development of the P220, SIG collaborated with J.P. Sauer & Sohn of Germany, thus, the P220 and all subsequent pistols from SIG are properly known as SIG Sauer pistols. The P220 operates by the locked breech short-recoil method pioneered by John Browning.In 1975, Switzerland became the first nation to officially adopt the P220 as the "Pistole 75" (P75) chambered in 9 mm Parabellum. Other nations to adopt it for military use include Japan and Denmark. It was succeeded by the SIG Sauer P226.