It was never intended that anyone shoot 38 supers in these guns, they were dual chambered by counterboring the chamber mouth for the larger rim of the 38 auto. The dimensions of the 38 Super and 38 Auto are the same, but chamber pressures are very different. At the very least longevity will be compromised, though the Star pistols are very well made. I advise caution, in fact I advise people to not shoot 38 super in any of the Spanish guns with the dual chamber markings, which is exactly the same advice the experts at the websites concerned with 9MM Largo chambered handguns give out. The 9MM Largo max pressure is about 28,000 lbs sqr inch, The 38 Auto max pressure 26,500 while the 38 Super 36,500 lbs sqr inch.
From the 9MM Largo website; "The vintage 9mm Largo firearms that are available were not designed to be fired with .38 Super ammunition! The metallurgy of your pistol was not designed to handle .38 Super pressures. It was designed to handle 9mm Largo, and some of them were designed to chamber .38 ACP. When the pistol was new it could probably handle a certain number of .38 Super rounds. As it nears the end of its service life it gets weaker from containing the pressures of firing and the mechanical action of functioning. Firing .38 Super in your 9mm Largo firearm is much like firing +P+ ammunition in a firearm not designed for it."
You do what you want, an argument could be made that the Star B model chambered in 9MM Parabellum (35K max) shoots a round with pressures very close to those of the 38 Super, and that the only difference between an A model (9MM Largo) and the B model is the chamber dimensions.
I have a pristine Star A model, but I will not shoot 38 Super in it even though it accepts both 38 Auto and 38 Super cartridges. The 9MM Largo chambered Star super 9MM is exactly the same in that regard.
