I reload what I shot and accumulated over many years. Sadly, in that time I didn’t shoot .380ACP, so I tended to toss it when I picked it up with 9. Consequently, when I started loading .380ACP, I had to acquire brass from generous forum members, as well as buying it once fired from Ammobrass.com.
I came to appreciate the European cases over good ol’ USA. Fiocchi has been my preferred brass, along with S&B, and my small hoard of Austria’s *HP*.
For US cases, WIN and RP are my best brass, no issues to speak of, except when my Lee sizing die started giving me problems I ruined mostly Blazer and WIN. I started to think that Blazer was simply garbage...until I got a new set of Lyman 9mm dies, their MSR package. Since the switch I haven’t tossed any cases except those that I damaged the mouth. Truth be told, I’m with Steve S and really don’t see or feel a big difference between these various brass manufacturers. The only real reason I prefer the European cases is their headstamps appear laser cut...they really stand our, and hold up even after several firings. The US headstamps seem to get distorted a lot easier, making sorting by headstamp, which I do religiously, more challenging.
For what it’s worth, I loaded up 100 380ACP today with the only Starline brass I have enough to fill a Berry’s ammo box. I’m guessing I’d need to load rifle brass if I wanted to notice any difference.