I finally got the chance to shoot my R9 again. I cleaned and relubed it as per the instructions prior to going to the range.
I shot 50 rounds and they were all Winchester white box FMJ.
Out of the 50 rounds I got 5 FTF, on rounds 14, 19, 24, 36 and 47 and it didn't matter which mag I used.
That's no better than the last range session when I got 6 or 7 FTF out of 70 rounds fired.
The wear on the inside of the frame rails didn't appear to progress any further this time, so at least that's one good thing.
I now have 120 rounds through the gun and it is averaging a FTF every 10 rounds. I don't really think it's a break-in issue, so I guess it's time to give Rohrbaugh a call and see what they say. I really hate shipping my guns out but I guess I have no choice.