IMHO Remington Golden Sabers are the only JHP that will expand and still consistantly penatrate. If I couldn't use that I'd probably just use ball (I'd also use imported Ball as domestic stuff is weaker)
I might even load the gun with GSs and the extra mag with ball.
Yeah, the best .380 is any you can find. Period. My LGS has not seen ANY in about 7 months. Another shop I know of has 3 boxes stashed in the back, and the only way to get a box is to buy a new gun chambered in .380 ; and they will only sell ONE box at that. Good luck.
FMJ. Maybe Buffalo Bore if it goes the distance inside flesh and bone. Hornady's Critical Defense looks very good but, i've heard some bad things about their primers not going off.
If you will look at the following link, there are many post on .380 SD ammo. http://elsiepeaforum.com/forum/index.php?board=8.0
Personally I have tried several different brands in my LCPs', Cor-Bon DPX, Hornady CD, Golden Sabers, etc. They all give good penetration & expansion. I carry Cor-Bon DPX in all 3 of my & my wife's LCPs.
If it makes you feel any better, there are a lot of folks who think that FMJ ammo in the .380 is just as good or better than HP ammo due to the marginal energy available from the .380 for penetration. As always, shot placement is far more important than the ammo used, all other things being equal.
I carry Buffalo Bore JHP in my Sig P238. I wouldn't carry it in a LCP/P3AT. Buffalo Bore tends to have them in stock most of the time, but they must be ordered online.
I like Corbon DPX and Hornady Critical Defense and Speer gold Dot. The guys over at KTOG (keltec) have alot of 380 ammo testing info. Go to the p3at section