I can't speak for the ejection problem but you may want to check if the front scope mount screw is contacting the barrel threads or if the front action screw is bottoming out.

That used to be a more common issue on Kimber Montana's effecting accuracy.

Here is a thread on common issues with Kimber Montana's:
http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/8486078/1


Despite my user name, no I am not from Texas.........