Honestly I think I printed it at .2, and that may be the difference. I a may tighten up the tolerance a little bit more.
The width of the hole fully open is the same as the dillon feeder, and I believe it will handle anything from .223 on up. So the slider really should only come in to play with things like .300BO. I also had a thought that my new long bullet collator plate could probably be used for 300bo brass very effectively.