Very tiny mold block lines I don't worry about.If the lines are more prominent, I measure the ball orienting the jaws of the calipers on the ball the same way the mold blocks hold it. If the increase in diameter is less than one or two thousandths, I don't care. Nor do I care about minor surface wrinkles. But I will inspect the surfaces of the blocks where they meet for ANY trace of lead or something that might keep the mold blocks from fitting up tightly together, and monitor the situation carefully.If the problem worsens, I will replace the mold. I have only had to do this once, and since it was a Lee mold, the expense was minimal. I also lightly tumble my bullets with a very small pinch of graphite, which is an excellent way to prevent surface oxidation, which can form over time if they are not used for months or years. By the way, if removing something stuck on the mold block faces, use some tool that is softer than the block material to prevent scratching.