Hi, new P380 owner from Pittsburgh reporting in! Here's my story...
I went to my local shop to look at a used LCP a couple of weeks ago, and then my friend at the shop pulled a used P380 out of the case. Damn, did it seem nice! I hated to spend twice the money, but couldn't help myself. I have a CM9 that I bought for pocket carry. I love the CM9, but never carried it much because it's a little too bulky for that. So I thought that the P380 would better serve the purpose that I originally bought the CM9 for.
Took it to the range, it ran like crap, and then the slide locked up on a live round - couldn't get it out. So I took it back to the store. Meanwhile, I started digging around online, learned about all the problems other people were having, and found that my "RB" serial number was part of a bad batch of guns. I called the shop, told them I was disappointed they sold me a gun that wasn't functioning well, and pissed that I'd be without it for weeks while they checked it out themselves and then sent it back to Kahr. I requested that they take it back for what I paid if I agreed to buy a new one at full price. It took some persuasion, but they finally agreed.
So now I'm breaking in a new P380 with black diamond finish. At 350 rounds it's not running perfect, but it's getting better. I've learned a lot so far, like keeping my thumb off the slide release so it catches on the last round. It's fun to shoot and it's surprisingly accurate. At the range yesterday, I was shooting better at 10 yds than a few off-duty cops with their Glocks! ;D It's a shame you have to go through so much effort to break in a gun and sort through the problems, but I like the gun enough that I'm willing to go through all of this.
Hope to get lots of good info from this site!