Now that I think about it...it may not have been that they were "uneven"....but then, it probably depends on what one means when one uses that term.
A few of my XCR bbl chambers were too tight. To me, that means the chrome plating process wasn't correct, resulting in either high spots or a uniformly too small chamber which caused extraction issues. Granted, that was now somewhere around 9 years ago. I don't know if the process has been significantly improved in the last decade or not....