The 9mm MJR (9mm Major) dates from around 1991 and was designed by Horst Grillmayer, who also developed the 9×25 SAG (Super Auto Grillmayer). It is based on the 40 S&W case necked down. As can be seen from the specimens below, some of the original testing was done in South Africa, the same as with the 9×25 SAG before production was moved to MFS in Hungary.