How many rounds did you fire? and were they all like that?
I`d look at the brass it`s self. If the brass is not uniform when made, basicly a bannana, one side thicker that the other, the thin side will swell, making it difficult if not impossible to rechamber with out resizing. My quess is nothing is wrong with the chamber, but is with the brass. You mentioned some cases were "tight" from the get go?
BTB, did you get a fired case from the smith? It should have been test fired, maybe several times. That would give you a clue.
Good Luck
