I am having a new problem with my P380 returning to battery;
The history for this is as follows:

1st trip to range:
Ran 250 rounds through the gun in one trip.
150 WWB
100 Remington UMC FMJ
12 Speer Gold Dot
Had 3 FTF in the first 100 rounds (2 wwb and 1 rem umc) and 1 FTRTB
Next 150 rounds were flawless and the gun was pretty nasty when I got done.

2nd trip:
1 clip of Federal Hydra Shok
1 stovepipe

At this point I was pretty happy with the gun. Wasn't gonna carry the Hydra Shoks so I didn't worry about the stovepipe.
Then my troubles began.

3rd trip yesterday;
I had 50 rds of wwb, 50 rds of Remington JHP and 1 box of Speer Gold dot.
Had no problems with the first 15-20 rounds.
Then started getting a failure to return to battery.
After 40-50 more rounds, it progressively got worse and wouldn't lock up with any of the ammo I brought . Needless to say, I was getting pretty aggravated.
At the time I thought the gun might just be getting really dirty, but I ran more rounds through it on my first trip with this only happening 1 time.
I cleaned the gun this morning and lubed the rails and contact points on the barrel up good and am still having the problem when locking the slide back and feeding a round.
With a full clip of Speer Gold Dot, it might completely lock up 2 times feeding 6 rounds in this way.
I polished the exterior of the barrel before this trip, but I would think that would help this issue instead of hurt.
I am pretty confident the recoil springs are in right and don't think the springs would be getting weak already.

I do plan on trying to polish the feed ramp and throat on the barrel and shoot the rest of the ammo I have to see if that helps.
Anyone else have this problem or have any suggestions?
Thanks