did it tonight (didnt have time before to play with that, and range is closed until spring anyway).
Took the lee FL die that I had ground quite a bit before. Removed the firing pin assembly + ejector assembly for a better feel.
Then adjusted very slowly to 1/16th of a turn until bolt closes with no resistance. Locked the ring, done.
I did all brass through the small base die + this die (all 1F brass from another rifle.)
Tested a few, they all chamber perfectly without resistance.
Tested a factory round, it will chamber, but with some moderate resistance. (does not really matter as I am not going to fire factory rounds anyway, and I can deal with moderate resistance if I need to shoot factory ammo, which will probably be less than 1% of the ammo anyway).
Ok, so just letting you know how it ended. Plan is to use that brass and just neck size from now on, unless it gets too tight.