El rifle implacable is a good, if not the best, Mexican western directed by Miguel M. Delgado. As typical of its time, the film explores justice by a heroic bandit/gunslinger. Antonio Aguilar takes the lead as wrongly-accused gunslinger Martín Pérez, who flees from the authorities with the help of beautiful, orphaned land heiress Luisa Vélez (portrayed by Flor Silvestre) and her conservative, fair- minded younger sister Ana Veléz (played by Colima-born Olivia Michel). On the condition of his help, the sisters also allow him to work as a ranch hand in their farm. Supporting cast includes brothers Víctor and Tito Junco, who play the villains. Also, "El Chavo del Ocho" star Ramón Valdés makes a cameo appearance. Japanese Mexican actor Noé Murayama goes uncredited as another villain by the name of "El Puma". The film is not bad, although it is not as entertaining or suspensive as other western films of the era, like "El revólver sangriento" (1964) or "El zurdo" (1965). It is a low-budget production that was filmed in Valle de Bravo. Throughout the whole movie only Aguilar and Silvestre sing, each one song. The film clearly was never popular, although it is memorable to watch. Overall, one could watch it as a timeless classic that is accompanied by good singing and good acting.