Sounds like a nice piece that should serve you for years to come .
According to Bill Wilson the number 1 problem with production 1911's is the makers fail to correctly tune the extractors causing the FTRTB issues you had .
If they continue you have three choices 1 send it back to Kimber , 2 take it to a local Smith for this simple fix or 3 do it yourself .
I did it myself on my Full size Charles Daly and it didn't take long at all or require any special tools .
I imagine it is simply putting to much pressure on the cartridge and needs the pressure reduced with a slight bend in the extractor .
Here are a few sights to help you with any problems you may have with this or other 1911's .
On the second sight look on the left and click on Technical Issues and then look in the box in the middle of the screen and you will find Extractor tuning and installation tips by Bill Wilson .