 This action first appeared in the United States on the Browning BDA (Browning Double Action) .45 ACP caliber handgun around 1975.It represents a design which optimizes the cost of production of handguns while instilling high levels of accuracy and dependability.It is the basis for several SIG Sauer, Inc. designs which have been widely adopted for police, military, and civilian use and is the action used in the M17 and M18 sidearms of the United States Armed Forces.