The pistol is new maybe 250 rounds spent. It has jammed since the beginning. No I haven't taken it apart yet but clean it every time I shot. Maybe back to Ruger is the right advice. I'll call them Monday morning.
For the sake of this issue, please define "clean" in this context. Have you pulled the bolt assembly out, disassembled it and given it a once over? I seem to recall my MKIII being somewhat gummy with the anti corrosion goop that they ship them with from the factory. FWIW, that stuff is not proper gun lube and I could see it gumming things up enough to cause issues. I ended up having to detail strip mine and toss everything in a parts washer to get all of it out.
Aside from that, I can say that CCI is my preferred brand, for the simple reason that it cycles everything and shoots accurately for me. The only feed issues I've ever had were the result of me failing to keep the mags adequately clean. My oversights aside, my MKIII has been excellent from a reliability standpoint otherwise.