Thought I would post a link to this article that makes mention of the same type of jam I was having in my Kimber. It is a write up of a three gun test of the exact same model of Kimber 1911. Seems they stopped having the issue after discontinuing use of two out of the six or so mags being used.
Kimber three-gun test: 6,000 rounds and a surprise or two | American Handgunner | Find Articles