The FM M Models, were designed because of an Argentinean Army request of a more modern pistol, as the newest handguns in the Argentinean Armed Forces were the Sistema Colt 1927 and the FM High Power "Rosarina" pistols, from 1927 and 1937.
Even though the M Models are Single Action pistols, they are improved designs of the "old" (but still efficient) "Rosarina" model. Newest models, like the M02 AR and M03 AR have new Fast Action (Acción Rápida in Spanish) designed by the Fabrique Nationale, which allows them to be fired like a Double Action, but still being a Single Action.
Although the M Models are improved Designs of the standard High Power, they are made by license of FN, because the actual design is the same as the Mark II Pistol.
These Pistols are very popular in Argentina and other countries, as they are considered very efficient pistols and after extensive use, they can still make a 3 inch grouping, which makes this pistols one of the most accurate Pistols of Argentinean manufacturing, and maybe one of the best handguns in 9mm (or .40S&W in the M03).