Have you ever BEEN IN A FIGHT? The odds of you even having a full second to pull the trigger 3 times on a 300# attacker is slim and NONE!the 3 rounds I can put center mass in about 1 second, should at the very least make him take notice.....now I have 5 rounds left, and when they hit him in the face, Im sure the threat will stop.
Even a .45 isn't always "enough", but then it's not really a matter of .380 being "enough" or not, it's this misconception you appear to have that a bad guy is going to STAND there and talk trash while you shoot him 3, 5, or 7 times with ANYTHING.
If you're having a good day, maybe you will see him coming so you can get your HAND on your pistol. IF you're lucky, you might even get your pistol fully drawn before you are within physical contact range. REAL lucky would constitute you being albe to POINT the muzzle in the general direction of the dude before he gets his hands on you or your pistol.... But now if you actually get the opportunity to aim AT ALL so as to get that presumed COM hit of yours, you better run out and play MegaMillions right away because lady luck is moaning your name brother!
Why do you suppose police officers 1) practice weapon retention and 2) get shot with their own guns so frequently?
Quite frankly, if you DO get to shoot a "bad guy" 7 times or more, especially with aimed shots, then you may have a VERY hard time claiming self defense in the first place since you had all that time to kill.
But to actually comment on the caliber itself... I'd rather have the most I could have in an effort to make ONE SHOT COUNT rather than count on multiple shots. Since 9mm pistols have NO MORE RECOIL than a .380, and since modern 9mm pistols are available that are the SAME SIZE as all but one or two .380's currently available, then you're stepping down a caliber and gaining absolutely nothing from it.
If you like the Bersa, that's great. If you want to carry it, that's great too. I've carried a .32 in my pocket, and carry a .38 snubby regularly which has no more power than a .380. But do re-think your victory scenario because it's not very realistic.