Perhaps we should repeat Bill DeShivs' question. Is the gun a Firestar or a Starfire?
As previously mentioned, the Firestar moniker was used on two Star pistols: the all-steel single-stack Model 43 Firestar and the alloy-frame double-stack Model 243 Firestar Plus.
The Starfire name was primarily used on some versions of the Star Model DK, a subcompact alloy-frame .380 single-stack pistol that served as the template for the Colt Mustang and, by extension, the SIG P238. However, some variants of the Star Model 30- a large double-stack DA/SA 9mm- were supposedly also marked "Starfire".
I would not use .380ACP+P in a Star DK. This is over-pressure extra-hot "boutique" ammo that is loaded in excess of industry standards. A hard-to-find vintage alloy-frame pistol is exactly the type of gun in which I would NEVER use this type of ammo!
If it's a Model 30, I don't know if it's
officially +P rated, but I would consider the pistol to be
unofficially +P rated as it is arguably the most overbuilt and ridiculously tough all-metal 9mm pistol this side of a SIG P226 or a S&W Model 5906. The pistol is likely to wear YOU out before you wear IT out.
As for the Firestar, I'm not so sure; anyone else care to chime in?