Unusual. I'm assuming that you sent the mag back with the Kimber. And I'm assuming that you used factory ammo. As chapin and blaze said, check your grip. Try different ammo. If that doesn't work, consider this:
I have a 1911. I will not mention the brand, but it is not a Kimber. When it was new, it would jam. At the time, I lived a few miles from the factory. I was sent to the private business of the company's chief assembly line manager, also a gunsmith. He noticed that the ejector was hitting the inserted magazine. (???!) He shaved a few mm off the ejector and the gun has been fine since.
Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote. NRA CSSA GOA 2AF CCRKBA / Tactical Pistol Instructor