Valad,
Congratulations on figuring out one of the "mysteries." Before you go further, I have a question:
Are these cases for an AR or a bolt-action?
If it is an AR, check your sized cases with the one-turn out, you might have to pull your upper and check bolt-closure that way on an empty case. It's a "feel" thing, but you don't want to have to use the forward assist to close the bolt. I set my dies so that gentle pressure on the back of the bolt carrier with only one finger, or the thumb "easy" closes the bolt. No grunting.
For a bolt rifle, you can set your cases with just a neck die if they have been fired in THAT rifle. They are now "fitted." Or you can back off the FL even further and just size most of the neck.
As for case lube, since I do big batches, when I have to lube, I will use Hornady One Shot and a pie pan to spray. Good stuff, worth the price, and less messy.
As for the vent hole, it's really not for lube but to release AIR. Keep it open, and make it a habit to clean your die well after a session.
