I've had other problems with my R-9, but never a Faiure To Feed (FTF), even though I've used a variety of ammo. I have fired about 390 total rounds with my R-9. 100 rounds of of this was Speer 115 grain GDHPs with no FTFeed problems.
There is one important thing I've learned after firing about 390 rounds with my R-9. YOU HAVE TO HOLD ON TO IT VERY VERY TIGHT! I have shot many hand guns in my life and I very seldom get a "limp wrist" type failure with my normal grip, even when firing my Kel tec P3-AT .380 with hot Corbon ammo. But using my normal grip on the R-9 was sometimes giving me failure to eject problems. So I griped my R-9 even tighter and these problems went away. Try it, maybe it will help with some of the problems. Good Luck.
Ed