I cleaned die again and also readjusted the expander ball. I set the ball a touch higher in relation to the vent hole on side of die body. Replaced aluminum die nut with steel Hornady nut. I also used nylon brush inside of necks. So far there are no bumped or pulled shoulders. I'm thinking the ball was a little low not allowing the vent hole to function as intended. I appreciate the help everyone!
So you're thinking vacuum sucked the shoulders forward by 4-5 thousandths? Or what?