When adjusting your sizing die, put shellholderon the press ram. Run the ram all the way up. Screw the die down till it touches the shell holder. Lower the press ram. Screw die down another 1/4 to 1/2 turn and set lock-nut. Know run the press back up and make sure it will still cam over although it should be a little tight. If it won't cam over, the die is down to far, if it cams over with very little or no resistance, the die is still up to far. Also check the adjustment of the seating die. If it's down to far it can deform the case right behind the shoulder and cause this problem. Put a resized empty case in shell holder and run ram all the way up. Screw die down till you feel it touch the case. Back up 1/2 to 1 turn and set lock nut. This should cure your problems. I personally resize my cases to give a slight resistance when closing the bolt. This tightens up headspacing and gives better accuracy in everything I load for.