What was the name of Al Capone's gun in Scarface?

In the 1983 film "Scarface," the character Tony Montana, played by Al Pacino, wields a gun called the "M16." This firearm is notably featured in the climactic scenes of the movie, showcasing Montana's rise to power and eventual downfall. The M16 has since become an iconic symbol of the film and is often associated with Montana's violent lifestyle.