I bought a new R-9S at the beginning of the summer. I shot about 200 rounds of Federal 115gr FMJ (cleaning and lubing with recommended products after each 50 rounds) with occasional failures to feed with rounds jammed up against the ramp. Interestingly, when two friends tried it at different times, it failed to feed on almost every round which I attributed (now I think wrongly) to limp-wristing although both are experienced pistol shooters.
Recently, I've tried JHP defensive ammo with really bad results. Speer 124gr GDHP failed to feed about 25% of the time and, even worse, with a fully loaded magazine, the first round would not chamber and unjamming it was hard. Winchester 147gr failed to feed 50% of the time but did not jam when trying to chamber a first round like the 124gr GDHP. I haven't tried any 115gr JHP rounds yet but I'm not optimistic.
I think the gun has to go back but if anyone has any ideas I'd welcome them.