Its a nice gun, I like mine. I tried the win 333 packs and they were terrible, about 30% wouldn't cycle the slide.
I mainly use the federal 525 packs, no problems if I keep the gun clean. I start geting ftf's after about 80 rounds of federal , then I need to spray the gun slightly.
I am amazed that you were able to fire so many rounds without cleaning it. I will have to try some American eagle and CCI to see if theres a difference.