I put about 250 rounds through my .380 Kel-Tec P3AT before it "smoothed up" and stopped having jamming problems, but now it seems to be doing just fine... it even feeds the aluminum-cased CCI Blazer ammo now. At first, it jammed constantly while using Blazer ammo. But after it passed the 250 round "mark", everything seemed to get better.
During the last 100 rounds of the 350 total rounds put through it so far, including (in the last 100 rounds), there was about 30 rounds of Blazer Ammo and 10 rounds of the +P ammo with the big cavities in the nose of the bullet that were used... and it fed without a "hitch".
In all fairness, I must say that I am using bullets with LARGE hollow-points in the nose of the bullet, not "ball" ammunition... but it now feeds the hollow points without jamming whereas during the first 200 or 250 rounds, it failed to feed, jammed or stove-piped quite a bit.
I'd give your P3AT a little more use... and if it still has problems, THEN send it back to Kel-Tec without hesitation.
My hunting buddy had to send his P3AT back to Kel-Tec in Florida... and when he got it back (about 3 weeks later), it worked flawlessly.
Strength & Honor...
Ron T