Neck sizing question

[Catfish]

There is 1 other problem you may run into. I have run into it with over sized custom chamber but not with a factory chamber yet. That is if your chamber is lagre you will not only partical size the neck but also the body of the case. When you size the body of the case much you will have a ring that runs just a head of your die. If you push it clear to the back of the case you will clean it up, but if not the ring may keep your rounds from chambering.