In my opinion (we all have them) you are correct in your first paragraph but totally contradict yourself in the second paragraph. Running your rounds thru the FCD will cause the problem you accurately state in the first paragraph because of the very same reason, especially if you're using cast bullets. Think about it. I know a lot of reloaders love the FCD, but that's my take on it and I only mention it because you appear to have a better understanding than most on the process. In addition, if you're using the FCD on cast bullets, you will resize them, which really negates the reason for cast bullets to be slightly oversized. I'm not harping on you, just putting out a little info you may not have thought about.