The name "The Savage Guns" was used for this Carreras film, and also for a 1971 Italian western. For the 1971 film the name was created for the US. The original title for that one was Era Sam Wallash... lo chiamavano 'Così Sia', which IMDB lists. The Spanish title for the Carreras 1961 film was Tierra brutal as IMDB lists.
I don't know any source for the 1961 movie, but the 1971 film is available.