1. Machine Setup and Operation Dirt prevents the blank mold from completely closing Neck ring and plunger are dirty   1. Machine Setup and Operation Change the dirty mold equipment Change all dirty neck rings and plungers   2. Mold Equipment Neck ring diameter is too small for the bland mold Blank mold dovetail too large for the neck ring Neck rings are not correct matched   2. Mold Equipment Increase the neck ring diameter Check blank mold dovetail with the mold gauge Change neck rings for a correctly matched pair