The case would probably go through the sizing die fine.
Likely the case would come out of the belling die flared way too much, and you'd see it when you went to seat the bullet. (Ever run a .357 case through a press set up for .38? Like that.)
If it made it through all that, The pistol probably would not go into battery, as the case is 1mm longer.
"As was the man of dust, so also are those who are of the dust, and as is the man of heaven, so also are those who are of heaven. Just as we have borne the image of the man of dust, we shall also bear the image of the man of heaven. "