Problems with accidental discharges and accuracy with the P.A.M. 1 led to an improved selective-fire version with a grip safety on the magazine housing known as the P.A.M. 2, first introduced in 1963.
* P.A.M.1 ("Pistola Ametrelladora Modelo 1") — лицензионный вариант под патрон 9×19 мм, производившийся в Аргентине с 1955 года на заводе FMAP в городе Росарио.